John Wentworth (March 5, 1815 – October 16, 1888), nicknamed Long John, was the editor of the Chicago Democrat, publisher of an extensive Wentworth family genealogy, a two-term mayor of Chicago, and a six-term member of the United States House of Representatives (serving tenured in that body both before and after his service as mayor).

After growing up in New Hampshire, he joined the migration west and moved to the developing city of Chicago in 1836, where he made his adult life.

Later that year, Wentworth joined a migration west and moved to Chicago, arriving in the city on October 25, 1836.

He was a business partner of Illinois financier Jacob Bunn, and the two men were two of the incorporators of the Chicago Secure Depository Company.

[citation needed] In July 1857, while serving as mayor of Chicago, Wentworth was charged with assaulting an attorney named Charles Cameron, who was attempting to communicate with his incarcerated client.

Cameron testified that Wentworth "seized him by the coat collar and shirt bosom" and forcibly removed him from the prison, alleging that he had resisted officers.

In 1857, Wentworth led a raid on "the Sands," Chicago's red-light district, which resulted in the burning of the area.

After retiring from Congress, from 1868 Wentworth lived at his country estate at 5441 South Harlem Avenue in Chicago.

He owned about 5,000 acres (20 km2) of land in what is today part of the Chicago neighborhood of Garfield Ridge and suburban Summit.

[15] The first [16] of the 1878 volumes chronicles the ancestry of Elder William Wentworth, the first of this family in New England, and his first five generations of New World descendants.