South Boston grew rapidly after the construction of the Old Colony Railroad, and flourished as the hub of industry in the years prior to the Civil War. Iron foundries, machine shops, shipyards and refineries all fueled the war effort. South Boston's rapid industrial growth attracted an influx of Irish immigrants. Irish-Americans continue to be a strong cultural force in the community and celebrate each St. Patrick's Day with a lively parade through the neighborhood.

In the 20th century, shipyard and railroad jobs continued to provide work for South Boston residents. Today South Boston’s commercial district lines East and West Broadway with a multitude of pubs, shops and restaurants such as Sullivan's. South Boston's waterfront boasts miles of beaches and coastal parks, including Carson, L Street and Pleasure Bay Beaches. Toward the end of the 19th century, landscape architect Frederick Law Olmsted created "the Strandway," which runs from Castle Island to Columbus Park.

Residents of Southie are famous around Boston for the fierce pride they feel for their neighborhood. Families often remain in the neighborhood for generations, inhabiting the characteristic Southie triple- deckers and row-houses. There are also single family homes in this long-standing community. Home prices here vary depending on size and proximity to the waterfront.