During World War II, the streets of North, Clark, and Ogden Avenues (which form a triangle) were designated a 'neighborhood defense unit' by Chicago's Civil Defense Agency. In the years immediately after the war, The population of “North Town” (as it was known) sponsored annual art fairs called the “Old Town Holiday.” The art fairs were popular attractions to the neighborhood and the name "Old Town" was used in the title of the Old Town Triangle Association when it was formed in 1948, by residents who wanted to improve the condition of buildings that were suffering from physical deterioration.
There is no legal entity known as Old Town, although claims have been made as to the nature of its unspecific borders.
Old Town is home to many of Chicago's older, Victorian-era buildings. The neighborhood is also home to St. Michael's Church, originally a Bavarian-built church, and one of 7 to survive the path of the Great Chicago Fire. Many of the streets and alleys, particularly in the Old Town Triangle section, predate the Great Chicago Fire and do not all adhere to a typical Chicago grid pattern.