CONSTRUCTION OF THE WASHINGTON MONUMENT, SECOND PHASE, 187684
CONCURRENT RESOLUTION OF JULY 5, 1876
As the centennial year of the establishment of the United States neared, Congress was stirred to complete the Washington Monument by a wave of patriotism that swept the Nation. On July 5, 1876, Senator John Sherman of Ohio introduced a concurrent resolution for the purpose. Referring to the approaching centennial of the independence of the United States and to the influence of George Washington in securing that independence, the resolution asked for appropriations to complete the construction of the Washington Monument in the following words:
The resolution was passed unanimously in two days by both Houses and in obedience to its instructions a bill for the completion of the Washington Monument was at once reported in the House of Representatives and became law August 2, 1876. 
This statute appropriated $2,000,000 for the completion of the monument, to be expended in four equal annual installments. It provided for the transfer to the United States of the ownership of the portion of the shaft already built by the Washington National Monument Society and it created a Joint Commission to direct and supervise the construction of the monument. The Commission was to report annually to Congress on the progress of the work and expenditures.
The Joint Commission was to consist of the President of the United States, the Architect of the Capitol, the Supervising Architect of the Treasury, the Chief of Engineers, War Department, and the First VicePresident of the Washington National Monument Society. On September 2, 1876, the Acting Secretary of State, the Hon. W. Hunter, informed William W. Corcoran, then First Vice-President of the Society, that the following persons were named members of the Joint Commission: President U. S. Grant, Edward Clark, Architect of the Capitol, James G. Hill, Supervising Architect of the Treasury, Brig. Gen. Andrew A. Humphreys, Chief of Engineers, and Corcoran himself.  The Joint Commission remained in authority until dissolved at its own request by the Act of October 2, 1888, exactly 12 years and two months after enactment of the legislation. For practical purposes, the Joint Commission created a Building Commission to handle details of the completion of construction of the monument. It consisted of the Architect of the Capitol, the Supervising Architect of the Treasury, the Chief of Engineers, and the First VicePresident of the Society. General Humphreys delegated his authority to Lt. Col Thomas L. Casey, C. E., who became engineer in charge of the project. 
THE ARMY INVESTIGATION BOARDS
A further requirement of the Act of August 2, 1876, was that,
Since the early days of its construction, apprehension had been felt about the foundation. It was believed that it was not of sufficient size to sustain the weight of the memorial column if carried to the height originally designed. These apprehensions were felt by few persons after the laying of the cornerstone, but by 1853 they had become widespread. In 1873, even after a lapse of 20 years, the question of the adequacy of the foundations again came up for discussion by a committee of the House of Representatives. 
Plans for the celebration of the coming centennial of the Declaration of Independence on July 4, 1876, were then being discussed. A specially created select committee of thirteen, representing the original 13 states, was considering the practicability of completing the Washington Monument by that time. These discussions resulted in a special investigation being made by a group of capable engineers whose conclusions were to the effect that the foundation should not be subjected to any additional load whatsoever. In other words, they stipulated that it would be unsafe to increase the height of the incomplete shaft, which then stood at 176 feet.
Despite the fact that it was not anticipated that further examination of the foundations would produce any evidence of instability other than that in the previously cited report, the Joint Commission procured the services of another board of experienced engineers to examine and to report on the foundations.
After careful borings, examinations, and tests of the earth of the site, and after weighing the evidence thus adduced, the Board completed its reports on April 10 and June 15, 1877. These reports concluded that the existing foundation was of insufficient spread and depth to sustain the weight of the completed structure, but that it was feasible to bring the foundation to the required stability by "hooping in" the earth upon which it stood. These opinions were concurred in by most of the engineers who had considered the subject, while they were nearly unanimous in their belief that to excavate beneath the old foundation and to put a new one beneath it would be extremely hazardous. (Colonel Casey did not share this belief.)
On November 8, 1877, the Joint Commission made its first report to Congress, summarizing the views and decisions of the engineers. This report led to the enactment of the Joint Resolution of June 14, 1878, authorizing the Joint Commission to expend $36,000, if they deemed it advisable, to give greater stability to the foundations. Almost two years had now elapsed since the creation of the Joint Commission.
The Commission immediately procured the services of an engineer and an assistant, and directed Colonel Casey to prepare a project for strengthening the existing foundation so that the obelisk could be carried to its agreed height of 555 feet.
In the preparation of the final investigation of the soundness of the foundations of the monument, the Board of Engineers was headed by Colonel Casey, and included P. H. McLaughlin, master mechanic, who had immediate direction of the work and workmen on the ground; Bernard R. Green, civil engineer, who conceived and worked out the plans for topping the shaft with a pyramidion; and Gustav Friebus Washington, architect, who drafted the detailed construction plans  under Colonel Casey's direction.
In passing it should be noted that in January 1877 the monument was formally deeded by the Washington National Monument Society to the Federal Government, which assumed responsibility for its completion.  The monument was not sold to the government as was believed in some quarters. 
THE "STORY" AND "MARSH" PLANS
For historical purposes some consideration should be given to the action that was taken in 1878 on the so-called Story plan for completing the Washington Monument. For a time it was given serious consideration by the Joint Commission and the Congress. This action was taken prior to enlarging the original foundations and the adoption of the pure obelisk form for the memorial as suggested by the Hon. George Perkins Marsh, U. S. Consul to Italy. Fortunately, as will be seen in due course, the Story plan was not adopted.
This plan was named for the American sculptor, William Wetmore Story, who was the sculptor of the obelisk commemorating the Battle of Bunker Hill that had been erected near Boston. Hearing of the contemplated changes in the design of the Washington Monument in 1878 due to the insecurity of its foundations. Story called on the Speaker of the House, Robert C. Winthrop, who lived in Boston. Winthrop had also delivered the principal speech at the laying of the cornerstone of the monument in 1848. Story presented sketches and ideas of his plan for the Speaker's consideration.
Winthrop, in commenting upon the visit of Story in a letter to Senator Justin S. Morrill of Vermont on August 1, 1878, said that he had told the sculptor that so far as he was concerned,
Meantime, Colonel Casey had been requested by the Joint Commission to examine a vertical section of the proposed Story modification, showing the relationship of the several parts of the Story plan to the existing structure on and its foundation, and to the enlarged foundation approved by the Joint Commission of September 28, 1878. Casey reported on January 29, 1879, that,
Casey also pointed out that the construction of the Story design would exert on the old foundation "a pressure far too great to be sustained by the soil upon which the present foundation rests." Apparently, there was some feeling in congressional and other circles that funds could be saved by adopting the Story design for, after showing the pressure that would be brought upon the enlarged foundation, Casey concluded,
Fortunately, art prevailed and the Story plan was discarded once the weight of better judgment was able to exert itself.
This was not the first plan that had been presented to Congress. When Congress decided to complete the monument in 1876, after the structure had been deeded to it by the Society, many designs were suggested that appeared to be less costly than the original Mills design. Many other plans had also been suggested to the Society.
The suggestion that most appealed to it was the design of George Perkins Marsh, then U. S. Minister to Italy, who was a lawyer by profession. Marsh's interests ranged from scholarly studies of comparative grammar to physiography. He gathered reptiles for the Smithsonian Institution. He had found the obelisks of ancient Egypt so fascinating that he had studied and sketched all that he had visited. Marsh's interest in on the Washington Monument was aroused when the Secretary of State in a circular letter to all diplomatic missions abroad, the usual form of communication for this type of request, sought information on monuments from its diplomatic representatives throughout the world.
Marsh's reply was spontaneous, direct, and to the point, "Throw out all the gingerbread of the Mills design and keep only the obelisk." he suggested. Marsh pointed out that based on his studies he had found that the heights of the best-known Egyptian obelisks, even though puny (being no more than 100 feet) compared to the plans for the Washington Monument, were almost precisely ten times the base dimensions. The shaft of the monument was 55 feet square at the baseline, therefore, the Washington Monument should rise to a height of about 550 feet and not to 600 feet as in the Mills design.
Marsh wrote to Senator George F. Edmunds of his native Vermont, "There will no doubt be people who will be foolish enough to insist on a peephole somewhere. If they must be gratified, the window should be of the exact form and size of one of the stone."  The Society adopted Marsh's ideas and construction work went ahead. The windows in the monument today are of the proportion suggested by Marshand the view from them is breathtaking.
STABILIZING THE FOUNDATIONS
By October 1, 1878, the Joint Commission for Completing the Monument and the Building Commission, including the Congress, had agreed that the height of the Washington Monument would be carried to 555 feet, and that its form would be an obelisk of the proportions recommended by Marsh. Active operations began immediately. The project contemplated first was digging the earth away from around and beneath the outer portions of the old foundation and replacing it with Portland cement concrete masonry; and second, the removal of a portion of the old masonry foundation from beneath the walls of the shaft and the enclosing of a new subfoundation by an enlargement of the area of the base with a continuous Portland cement concrete mixture.
Colonel Casey's investigations had revealed that the weakness of the old foundation lay in the fact that it was too shallow and covered an area of ground insufficient to sustain the pressure of the contemplated project. In other words, the strengthening of the foundation included enlarging the foundation by spreading it over a greater area and sinking it to a greater depth into the earth. 
Lumber and materials were contracted for immediately and contracts let with the following firms presumed to have been in the local Washington area: Willett & Libbey, one lot of scheduled lumber; Henry I. McLaughlin, 1,700 cubic yards of broken stone; T. T. Fowler & Co., 300 cubic yards of bluestone gneiss; I. B. White & Bros., 2,500 barrels of Portland cement; and R. M. Miller & Son, 1,500 cubic yards of sand. All these materials were used in the strengthening the foundation as shown by Table II which gives more detailed information on these construction supplies.
By January 28, 1879, all deliveries had been made on the contracted materials, including the delivery of the necessary tools and machinery to complete the required preliminary work and the setting up of shops on the monument grounds for the hordes of carpenters, masons, stone dressers, blacksmiths, drivers and laborers engaged in the enterprise. Briefly, the following work was performed before construction could be started: The top courses of the previously constructed shaft (176 feet) were secured from the weather. Further operations included the building of a carpenters and rigging shop, 28 by 60 by 12 feet; a cement storehouse, 24 by 100 by 10 feet; and a blacksmith's shop, 24 by 37 by 12 feet, equipped with three forges and the necessary ironmongering tools.
The roof of the lapidarium used for the storage and exhibition of the memorial stones was renewed and small rooms installed at both ends of the building for administrative purposes. A tenton capacity weighing scale was set up and a roadway from Fourteenth Street to the site of the monument grounds was graded and tamped with broken stones. The frame of a 36 by 73 by 16foot stonecutting shed was prepared to be set up when needed.
Six large wooden platforms for receiving and storing concrete were erected to receive the previously mentioned foundation materials. Oak and pine lumber for framing the first four cuts and tunnels to be constructed under the monument were delivered. Five boom derricks were erected about and atop the obelisk with all the necessary blocks and tackle. Two concrete mixers and two steam engines to drive the mixers and to carry the fall of the derricks were delivered and set up.
The old damaged roof and combination of derricks that were atop the monument from the earlier construction phase were removed and a new staging to carry a derrick was placed in position just below the upper surface of the monument.
Two bench levels to be used as points of reference during the construction of the monument were set up to the south and southeast of it. Spots were prepared in the foundation from which a daily series of levels of the structure could be taken as the work advanced. Excavations were made for the mixers and about 580 feet of four-inch drainpipe was laid to drain the water from these and other contemplated excavations.
With the working materials and supplies sufficiently stockpiled to assure the execution of his plans which had been arranged to the minutest detail. Colonel Casey ordered excavation to begin beneath the monument on January 28, 1879. He anticipated completion of the new foundation within 16 months. As Congress had not voted sufficient funds by the Joint Resolution of June 14, 1878, for completion of the foundation alone which Casey estimated would cost about $100,000, it enacted another Joint Resolution on June 27, 1879, granting a further $64,000. Casey expended a total of $94,474 on stabilizing the foundation. The work was completed on May 29, 1880, as planned. 
The mortar was a concrete mixture of one part Portland cement, two parts sand, three parts pebbles and four parts broken stone. Before Casey approved its use, an eightinch molded block of the material was tested. It showed its first crack at a pressure of 105,000 pounds; the maximum pressure fracturing it was about 122,000 pounds, or 1906-1/4 pounds per square inch.
By the close of the year, November 30, 1879, the mass of concrete below, the old work had been completed and operations begun on the underpinning beneath the shaft for the purpose of widening the old foundation and of transmitting the pressure of the obelisk over the completed masonry. Six sections of the underpinning, namely, sections No. 1, 2, 3, 4, 5, and 6 had been completed.  The remaining portion of this work, involving the removal of rubble masonry in 19 additional sections and the building of an equal number of sections of the enlarged foundation, was to be completed by May 29, 1880, the following year. 
In the operation involving the widening of the foundation immediately below the shaft, 2,098 cubic yards of rubble masonry were removed and 3,489 cubic yards of concrete built into the new work. Fifty-one per cent of the contents of the old foundation were removed and 48 per cent of the area of the base of the shaft undermined. The overall area of the foundations, including both the old and the new, were extended to 16,000 square feet and the depth to 36 feet, 10 inches.
In summary and according to one of the annual reports of Colonel Casey, the work of underpinning the Washington Monument and of stabilizing its foundations consisted of
When the subfoundation was completed on November 1, 1879, a 17,000 ton lead had been placed upon it for testing purposes. No appreciable change was caused in the relative levels of the four corners of the shaft by this weight. The average subsidence of the four corners of the monument during 1879 was .51 inches.
During the underpinning program, the monument showed an even settling of two and one-half inches. Throughout the entire construction of the monument, it settled only four inches. The 81,120ton weight of the completed obelisk was to be so well distributed that it is estimated that a 145-mile-per-hour wind would not topple it. A 30-mile hour wind causes a sway of but 0.125 inches at the peak. 
The stabilizing of the foundation involved the shifting about of certain machinery and the laying of an embankment about the base.
On June 7, 1880, work began on covering a portion of the new foundation with the earth that had been excavated from about and beneath the old foundation. By July 10 this embankment was completed and provided a terrace surrounding the monument 30 feet wide and 17 feet high above the general surrounding surface of the site. In 1881 it was enlarged to a 155by 220feetsquare embankment, consisting of 11,810 cubic yards of added material, including fragmented gneiss rock that had been excavated from the base of the old foundation.
This work also involved the shifting about of machinery and of the railroad tracks that previously had run right up to the base of the structure. A trestle was built at the base to raise the track above the embankment so that loads of marble and granite blocks could be hoisted directly into the east door of the monument, thus delivering them to the elevator on the ground floor and speeding up operations. Higher retaining walls were also built about the boiler house supplying power to the elevator, and two derricks and a small hoisting engine that had worked as a unit were shifted to new positions. Work could now be speeded up on completing the ironwork and the shaft.
Last Updated: 18-Nov-2003