|The Ottawa East Side Historic District is eligible for listing to the National Register of Historic Places under Criterion C as an intact assemblage of residential architecture representing both high-style, architect-designed houses and vernacular structures spanning nearly 100 years. Ottawa's East Side remains one of the city' s most diverse collections of high-style architecture, with a number of significant Greek Revival , Italianate, Queen Anne residences from the 19th century, and Prairie, Craftsman, and Revival-style houses from the early 20th century. The district is also eligible under Criterion A, community planning and development, as a neighborhood with a unique geography and development history in Ottawa. Located on a peninsula created by the Illinois and Fox Rivers, the East Side Historic District developed as an exclusively residential area through the 19th and early 20th centuries. Because of its relative isolation from Ottawa's central business and commercial district, the East Side became a prime location for the city's early professional class, who built gracious homes on large lots, many overlooking the Fox River. As the neighborhood matured through the early 20th century, a mixture of larger homes and more modest structures were built throughout Green's original 1835 Addition, creating a more varied building stock that reflected the district's broad appeal to homeowners in Ottawa. The period of significance for the proposed district is from 1848 to 1940. The year 1848 marks the date of construction of Henry Green's house, the first to be built within the East Side district. The year 1940 marks the point at which the East Side Historic District reached residential maturity.