South Chicago, formerly known as Ainsworth, is one of the 77 community areas of Chicago in Illinois, United States.

This chevron-shaped community is one of Chicago's 16 lakefront neighborhoods near the southern rim of Lake Michigan 10 miles south of downtown. A working-class neighborhood, it is bordered by East 79th Street on the north, South Chicago Avenue (the Chicago Skyway) on the southwest, a small stretch of East 95th Street on the south. With the Calumet River on the community's southeast side, South Chicago can be considered the gateway to the Calumet Region and one of the four Chicago neighborhoods (East Side, Hegewisch and South Deering) that are considered by the locals as part of Chicago's Southeast Side. The Southeast Side is a description that the city itself continues to resist, including this neighborhood with all of Chicago's South Side communities.

Once a separate community, South Chicago began as a series of scattered Native American settlements before becoming a village. First occupied by a chief named Askhum, considered 'lord' of the vast Callimink (Calumet) Valley and leader of the Pottawatomie people. They and other Native peoples used South Chicago and the shallow Calumet River area as portages, for seasonal settlements, hunting and fishing thousands of years before White settlers arrived to the "New World".

The post-Civil War era brought with it great industrial innovation. Developer James H. Bowen, the "Father of South Chicago," and others in a massive land grab wrested the land from its former existence and founded "Ainsworth" among other communities. This community was formed out of wetland prairie to provide residence for the labor force of European immigrants coming to work at the industries developing along the Calumet River, most notably the North Chicago Rolling Mill Company, built at the mouth of the river in 1881. Only fractions of the original topography and habitat remain as is the case with most of urban Chicago. With the entire Chicago Lakefront built on miles of landfill and slag there still remains a small stretch of semi-secluded beachfront just north of the Southworks Site. This bit of lakefront, once a seasonal settlement for the Pottawatomie, was left alone due to an unmovable and deeply embedded bedrock of granite, which defied the development techniques of the time. It is the only natural beach frontage left and virtually unknown on the entire Chicago coastline. This beachfront and the massive outcrop of the Southworks table slag to the south and the water treatment plant to the north is a perfect demonstration of the vigorous advancement of the steel industry and 20th-century development.

The four communities of Ainsworth; the Bush, Millgate Cheltenham/South Chicago and Calumet quickly developed into one village referred to collectively as South Chicago during the wave of annexation in 1883. The predominantly woodframed architecture of the Bush, Millgate and eastern Cheltenham are a lesson in Victoriana with the 'sunken yards' and bridge-like walk ups from street like Houston, Baltimore and Brandon attesting to the degree infrastructure built up from the original topography of that time. It also demonstrates how South Chicago was not immediately affected by the housing ordinances restricting the use of lumber for home building after The Great Fire of 1871. Most of the neighborhood north of East 83rd Street and west of South Manistee Avenue was developed after WWII and contain mostly brick homes, but under the ordinance brick homes began being built throughout the newly annexed neighborhood after 1883.

South Chicago was bustling with waves of immigrants as the popularity of the World's Columbian Exposition of 1893. The steel mill became U.S. Steel South Works in 1901, continuing to attract immigrants from Ireland, Eastern Europe, Scandinavia and Italy. During the 1950s many residents called the northeast section of South Chicago *"The Bush" and worked in the local massive steel mill, US Steel. Others worked in neighboring steel mills such as Youngstown Steel, Republic Steel, Bethlehem Steel, and LaSalle Steel. At its zenith, South Chicago helped make the Chicago metropolitan area the leading producer of steel products in the nation. The Willis (Sears) Tower and the Hancock Building were built from South Chicago steel. The embers, (graphite) from the smokestacks would cause the cars and sidewalks to sparkle and created a golden glow throughout the night. Softball and bowling were popular pastimes. Large Polish weddings on Saturdays were also a common sight.

Throughout the early 1910s, Mexicans from a variety of regions within Mexico began to settle in communities throughout Chicago including South Chicago. South Chicago became one of the first growing Mexican communities in Chicago. The community faced many challenges including many racist attacks by the more assimilated groups. The early Mexican community began to band together and worked to help build Our Lady of Guadalupe Church as they were not welcomed in other churches throughout the area. South Chicago's Mexican Patriotic Club's Mexican Independence Day (Sept. 16th) Parade was the first such parade in Chicago also celebrated with a carnival of rides and booths.

While South Chicago has a sizable African American population, existing ethnic groups continue to have strong community ties in the area. Our Lady of Guadalupe is the oldest parish founded by Mexicans in the City of Chicago. Immaculate Conception, St. Michael's, two churches built in the 'Polish Cathedral style' and later Saint Bronislava have served South Chicago's Polish residents for over 80 years and now have significant sized Latino populations as well. The first Catholic parish established in South Chicago was St. Patrick, which was founded by Irish Catholics.