Oak Park was settled beginning in the 1830s, with rapid growth later in the 19th century and early 20th century. It incorporated in 1902, breaking off from Cicero. Development was spurred by railroads and street cars connecting the village to jobs in Chicago. Architect Frank Lloyd Wright and his wife settled here in 1889. Population peaked at 66,015 in 1940. Smaller families led to falling population in the same number of homes and apartments. Oak Park includes three historic districts for the historic homes: Ridgeland, Frank Lloyd Wright and Seward Gunderson, reflecting the focus on historic preservation