South Trenton was incorporated as a borough by an act of the New Jersey Legislature on February 28, 1840, from portions of Nottingham Township.

In recent years, South Trenton has been experiencing a sharp rise in residents from Latin America, especially Puerto Rico.

The Sun National Bank Center was completed in 1999 and hosts hundreds of events per year from hockey games to musical concerts to job fairs as well as the very popular PrimeTime Shootout showcasing some of the nation's best talent in high school basketball.

The 2003 PrimeTime Shootout was the site of the highest-scoring game of LeBron James' high school career.

It is the Class AA-affiliate of the New York Yankees (formerly the Detroit Tigers and the Boston Red Sox) and counts Tony Clark, Carl Pavano, Trot Nixon, Nomar Garciaparra, David Eckstein, Dioner Navarro, Chen Ming-Wing, Phil Hughes, Robinson Cano, Melky Cabrera, Joba Chamberlain, Ian Kennedy, Bret Saberhagen, Derek Jeter, Bernie Williams, and Roger Clemens (the latter four as injury rehabs).

Another very famous landmark of South Trenton and Chambersburg is the famed and renowned Italian Peoples Bakery.

In 1831, John A. Roebling migrated from Germany, moving to Trenton in about 1848, when he purchased some acres of land on South Broad Street where his new wire plant would be located.

An analysis of households based on city directories of this period charts the composition of the neighborhood.