A "Triangle of Defense" was designed by Army engineers to guard the entrance of San Francisco Bay, with forts at Alcatraz Island, Fort Point, and Lime Point. The landowner of Lime Point and the government could never agree on a price, and that fort was never built. In 1853, construction began on Fortress Alcatraz, which was built atop the sandstone island, and Fort Point, a traditional casemate fort built at water level after massive excavation of the bluff. Alcatraz was completed first and became the most powerful of all Pacific Coast defenses. (map of SF Bay)

"Nature seems to have provided a redoubt for this purpose in the shape of Alcatrazes Island -- situated abreast the entrance directly in the middle of the inner harbor, it covers with its fire the whole of the interior space lying between Angel Island to the North, San Francisco to the South, and the outer batteries to the West....A vessel passing directly to San Francisco must pass within a mile." the Board of Engineers for the Pacific Coast , 1852

The rugged topography of Alcatraz was incorporated into the defense plan of the island. Blasting at the rock and laying brick and stone, laborers created steep walls around the island. Behind the walls, smooth-bore Columbiads were placed at the north, south, and west sides to provide gunfire at incoming enemy ships. Eventually 111 cannon almost encircled the island, and the gun batteries were named for prominent Civil War Union officers. North and south caponiers, masonry towers jutting out from the island midway between gun batteries, held smaller Howitzers to protect the sides of the island. Crowning the island near the lighthouse was a defensive barracks called the citadel.

The citadel was the final defense if the island was attacked. Constructed of sturdy brick walls with rifle-slit windows, the two upper stories provided living quarters, and the basement rooms were kitchens, dining halls, and storage of food, water and ammunition. Soldiers entered the citadel by crossing a drawbridge over a deep dry moat that surrounded the building. The citadel could hold 100 men during peace time and double that number under attack. By rationing provisions, troops could withstand a four month siege.

Due to the high walls, the island was accessible only from the dock. From the dock to the citadel, attackers had to get through the guardhouse. The guardhouse had Howitzers aimed toward the dock from each side room, and rifle slits for shooting enemies at close range. A dry moat and drawbridge, and heavy iron studded wooden doors blocked the road and prevented attackers from reaching the rest of the island.

Work progressed slowly on the fort. Finding laborers was difficult because newcomers to California were more interested in acquiring wealth through mining or establishing businesses rather than working for wages. Good quality building materials were hard to find. Many batches of brick were rejected before the citadel was built. Sandstone was quarried on nearby Angel Island, but much of the granite was imported from China.

By December 1859, the fort was ready. Captain Joseph Stewart and 86 men of Company H, Third U.S. Artillery took command of Alcatraz Island.

The fort on Alcatraz took on a new role during the Civil War. As the rumblings of discontent on the East Coast erupted into gunfire in April 1861, Alcatraz defended the Union state of California from possible seizure by Confederates. California's population included both Union and Confederate supporters, and tensions ran high. Colonel Albert Sidney Johnston faithfully did his duty to calm the threat of war locally and protect San Francisco until he resigned his command. After returning to the South, Johnston accepted a commission in the Confederate Army and died at the battle of Shiloh.

Johnston's replacement immediately ordered all military forces around San Francisco Bay to be on full alert. With many new enlistees, the military personnel on Alcatraz increased to over 350 by the end of April 1861. New troops arrived, underwent training, and departed for other assignments, some to battlefields on the East Coast.

The first threat to California's security occurred in March, 1863. The government learned that a group of Confederate sympathizers planned to overtake San Francisco Bay. The plan was to arm their schooner, the J.M. Chapman, and use it to capture a steamship which would raid commerce in the Pacific. They wanted to blockade the harbor and lay siege to the forts.

The Confederates' plans were thwarted when their ship captain bragged about their scheme in a tavern. On the night the Chapman was to sail, the U.S. Navy seized the ship and arrested the crew. The Chapman was towed to Alcatraz, where an inspection revealed cannons, ammunition, supplies, and 15 men hiding. One of these men, a prominent San Franciscan, had papers signed by Confederate President Jefferson Davis ensuring him an officer's commission in the Confederate Navy as a reward for this daring plot.

Rather than becoming Confederate heroes, the three ringleaders were arrested as traitors. They were confined in the Alcatraz guardhouse basement during the investigation. After a quick trial and conviction for treason, they were later spared ten years imprisonment on Alcatraz by a pardon from President Lincoln. The Unionists in San Francisco were shocked by the incident and feared that other Confederates were plotting in their midst.

In October 1863, an unidentified armed ship entered San Francisco Bay. Because there was no wind, the flag hung limp and men in rowboats towed the ship. The ship did not head toward the San Francisco docks. Instead, it traveled toward Angel Island to the North Bay, toward the army arsenal and the navy shipyard. The commanding officer at Alcatraz had a duty to ensure that no hostile foreign warship entered the bay.

Captain William Winder ordered the Alcatraz artillery to fire a blank charge as a signal for the ship to stop. The rowboats continued pulling the ship. Winder then ordered his men to fire an empty shell toward the bow of the ship, a challenge to submit to the local authority. The ship halted and responded with gunfire, which Winder confirmed was a 21-gun salute. Through the smoke, the Alcatraz troops could finally see the British flag waving on the H.M.S. Sutlej, flagship of Admiral John Kingcome. Alcatraz responded with a return salute.

Soon messages were exchanged rather than gunfire. As Commander-in-Chief of the British Navy in the Pacific, Kingcome wrote that he was displeased at his reception in San Francisco. Captain Winder explained his actions by saying, "The ship's direction was so unusual I deemed it my duty to bring her to and ascertain her character." The U.S. Commander of the Department of the Pacific supported Winder and replied that Kingcome had ignored the established procedures for entering a foreign port during war. Winder later received a letter of gentle reminder to act cautiously. Some San Franciscans thought Winder may have saved the day, considering that Great Britain favored the Confederacy.

Capt. Winder found himself in an awkward situation the next summer when he authorized commercial photographers Bradley and Rulofson to take photos of Fortress Alcatraz. Prints of the 50 photos were to be sold to the public to offset the photographers' expenses. The War Department in Washington, D.C. did not commend Winder for his initiative and pride in his post, but rather questioned Winder's motives because his father was an officer in the Confederate Army. The Secretary of War ordered all the prints and negatives to be confiscated as a threat to national security. Later, Captain Winder humbly requested a transfer to Point San Jose, a small defense post on the mainland.

As the Civil War lingered on and the Union seemed likely to win, the U.S. Army was willing to devote more resources to the Pacific Coast. In 1864, the first 15-inch Rodmans were mounted on Alcatraz. After the war ended, noted photographer Eadweard Muybridge was allowed to photograph neatly dressed military personnel posed around these mighty cannon. (photo)

Additional soldiers' quarters called a "bomb proof barracks" were approved. This two-tiered brick casemate building would hold 22 cannon to guard the dock. The upper tier would house 500 men, and the lower tier would hold four months of provisions. Excavation began in 1865, but because of lack of funds and obsolete design, only one tier of casemates was completed and the cannon were not mounted.

The end of the Civil War in April 1865 marked the end of Alcatraz as an effective harbor defense. Although there were over one hundred cannon on the island, these smooth-bore cannon were obsolete. New rifled-bore artillery had a longer range, and were more accurate and powerful against masonry forts. As if signaling the end of an era, the Alcatraz gun batteries fired the official mourning salute during San Francisco's honorary funeral procession for President Lincoln. The old guns were gradually removed from Alcatraz, and by 1891 there were only seven cannon mounted.

The island endured another topography change as new low-profile earthwork defenses were attempted. Army engineer Major George Mendell's "Plan of 1870" designed new defenses which could withstand the impact of rifled projectiles. Cliffs behind the old gun batteries were cut down, and rock was dumped in front of the walls. Pairs of Rodman cannon were separated by traverses, rocky hills covered with dirt and grass. The traverses contained powder magazines and tunnels to allow access to ammunition and other gun emplacements. Only initial excavation work was completed for the earthwork batteries, but some of the imported soil was used for flower gardens around the officers' quarters. At the same time, the south end of the island was leveled into a military Parade Ground. (photo of earthworks)

In July 1876, San Francisco celebrated the Centennial of the United States by demonstrating military prowess. Cavalry and infantry units performed maneuvers on the mainland, followed by a staged battle over the bay. All army forts and navy warships would shoot at a flag on Lime Point and at an old schooner loaded with explosives. Crowds gathered on the San Francisco hills in anticipation of a impressive gunfire display. As the battle wore on, the military became increasingly embarrassed as the old cannon were not accurate enough to hit the boat. Finally, under cover of gunsmoke, a young officer was sent in a tug to light the fuses on the schooner. The explosion proved anticlimactic, as spectators and military personnel realized the defenses of San Francisco Bay were inadequate.

Alcatraz Island was originally planned as an army defense site, but it also was a good location for a prison. When Captain Stewart arrived in 1859, eleven of his enlisted men were incarcerated in the guardhouse basement. Two months later, Alcatraz received Pvt. Matthew Hayland, "an insane man delivered for confinement and safekeeping." Soon Fort Point and the Presidio sent their deserters, escapees, thieves, and drunkards to Alcatraz, which was more secure than their garrison stockades. In 1861, Alcatraz was officially designated the military prison for the Department of the Pacific.

During the Civil War, Alcatraz imprisoned local civilians arrested for treason. The Confederates from the Chapman joined military prisoners in the guardhouse. The Chairman of the California Democratic Committee was arrested and sent to Alcatraz after making an "incendiary" speech during the 1864 Presidential campaign. He was released after posting bond and swearing an oath of allegiance to the Union.

The number of prisoners continued to increase. When the Howitzer rooms of the guardhouse were filled with prisoners, Alcatraz needed a more suitable prison facility. A temporary wooden prison was built in 1863 just north of the guardhouse, but later it was replaced with several adjoining structures called Lower Prison. This prison complex housed an average of 100 men throughout the late 1800s.

The army prisoners labored as part of their punishment. Some prisoners excavated and constructed new fortifications and housing at Alcatraz, and others went on daily work details to nearby military posts. Untrustworthy prisoners were given simple indoor tasks or confined in their cells on Alcatraz. Prisoners were identifiable by their obsolete uniforms with a "P" on the back of the shirts, jackets, and hats. (photo)

Many Native Americans were imprisoned at Alcatraz after troubleswith the U.S. government during westward expansion in the late 1800s. Some were the army's own Indian Scouts, who were convicted of mutiny. The army sent Paiute Tom to Alcatraz on June 5, 1873, but he was shot by a guard two days later. Broncho and Sloluck were arrested for participating in the murder of members of a peace commission during the Modoc Wars in northeastern California. The older members of their group were hanged, but President Ulysses S. Grant spared these two young men and sent them to Alcatraz. Broncho died of disease on Alcatraz, and Sloluck remained five years, then joined the remaining members of his tribe exiled in Indian Territory. Kaetena, a Chiricahua Apache chief who was a compatriot of Geronimo, was imprisoned for two years on Alcatraz. Upon his release, the army said "His stay at Alcatraz has worked a complete reformation in his character."

In January 1895, nineteen Hopis were sent from northern Arizona to the Alcatraz prison. These Hopi village leaders were involved in land disputes with the government, and they refused to comply with a mandatory government education program for their children. Besides sawing large logs on Alcatraz, some of the Hopis were given tours of San Francisco public schools "so that they can see the harmlessness of the multiplication table," according to a San Francisco newspaper. The Hopis were released after they pledged to "cease interference with the plans of the government for the civilization and education of its Indian wards," although they continued their resistance of government policies after returning to Arizona. (photo)

During the Spanish-American War, thousands of troops going to and from the Philippines passed through San Francisco. Many soldiers returned with contagious tropical diseases, and all local hospitals, including Alcatraz's, were filled with convalescing patients. Many other soldiers returned as prisoners and Alcatraz was quickly overwhelmed. Between 1899 and 1900 the prison population grew from 25 to 441.

Another prison complex was hastily built on the Alcatraz parade ground in early 1900. Upper Prison consisted of three wooden cellhouses with two tiers each, surrounded by a stockade fence. As additional support buildings were added to the complex, Lower Prison was converted into work space for prisoners. (photo)

Both Lower and Upper Prison were firetraps. An oil lantern fire almost destroyed Lower Prison in 1902, and prisoner/arsonist George "Firebug" Bender wanted to burn down Upper Prison. During the 1906 earthquake and fire chaos in San Francisco, a firestorm approached the city jail. Officials evacuated 176 city prisoners to Alcatraz for nine days. Alcatraz needed new fire-resistant buildings.

The army made changes on Alcatraz. Prisoners constructed a concrete barracks above the brick casemates of the bomb-proof barracks. Military prison guards replaced infantry soldiers, and the island was re-designated the "Pacific Branch, U.S. Military Prison, Alcatraz Island" in 1907. The army finally acknowledged that the future of Alcatraz was as a prison and not a defense site.

Major Reuben Turner, a talented construction engineer, quickly began an ambitious building project. Army prisoners tore down the upper citadel and built a huge cellhouse over the citadel basement and moat. The cellhouse complex included four cellblocks with a total of 600 cells, a kitchen, dining hall, hospital, recreation yard, and administrative offices. It was the largest reinforced concrete building in the world when completed in 1912. Turner also supervised construction of a power plant which produced electricity and steam heat for the island. (photo)

The army soon realized that this huge prison complex did not portray an image of military obedience and loyalty. In 1915, the island was re-named the "Pacific Branch, U.S. Disciplinary Barracks" and new emphasis was put on education and rehabilitation. The prisoners attended military training, remedial education, and vocational training. Many were restored to full duty after their sentence was served, although some were issued a dishonorable discharge.

Public disapproval of the army's prison resulted in new landscaping projects on the island. Some prisoners were trained as gardeners and planted lawns of clover and bluegrass as well as roses, sweat peas, and lilies on the eastern side of the island. In 1924, the California Spring Blossom and Wild Flower Association contributed 100 pounds of nasturtium and poppy seeds and 300 trees and shrubs to beautify Alcatraz Island.

As a disciplinary barracks, Alcatraz was a minimum security institution. Most prisoners were locked in their cells only at night and spent their days going to work, classes, and recreation. Work assignments varied according to how responsible the prisoners were. Some prisoners were house servants and baby-sitters for the army officers' families. Others crushed rock in the quarry on Alcatraz. Punishment for disobedience meant being locked in prison's solitary confinement cells or being chained to iron rings in citadel below.

Naturally some prisoners took advantage of the low security. While on work assignments at mainland army posts, prisoners sometimes snuck away to town. Escape from the island was more difficult, but several prisoners used deception to board a boat headed to the mainland. Most prisoners who tried swimming or clinging to wooden objects never made it to shore; some were rescued and returned to the island, others drowned.

The island's location proved to be the army's worst problem. The prisoners could do most of the labor on the island, but importing water, food and supplies to Alcatraz was very costly. Because of the Great Depression of the early 1930s and continuing negative publicity, the army closed Alcatraz and transferred most of the prisoners to Fort Leavenworth, Kansas and Fort Jay, New Jersey. When the army left the island in 1933, they turned over their 32 worst prisoners to the custody of the federal Bureau of Prisons.

The army continually sculpted Alcatraz Island for their needs. The mighty fortress was replaced with prison facilities. The citadel was buried under the cellhouse, cannon were removed and new workshops and military housing were built in their place. Discover what remains of Fortress Alcatraz and the military disciplinary barracks as you tour Alcatraz Island today.