The Logan Square Boulevards Historic District is a linear historic district in Chicago's Logan Square community area which encompasses 2.5 miles (4.0 km) of the city's boulevard system. The district includes sections of Logan Boulevard, Kedzie Avenue, and Humboldt Boulevard; it also includes two parks, Logan Square and Palmer Square, which connect the boulevards. Grassy medians run down the center of the boulevards; the medians and the two squares both provided recreational areas for residents and drew development to the area. Logan Square also includes the Illinois Centennial Monument, which was erected in 1918 to celebrate Illinois' centennial. The boulevards pass through residential areas and are lined with homes in a variety of architectural styles; some of the most common designs are sandstoneRomanesque houses, gray stone Victorian houses, and brick buildings with Tudor Revival and Prairie School designs.