In Brooklyn, a mob composed largely of Irish Americans attacked a group of African Americans in a riot.

Brooklyn is the most populous of the five boroughs of New York City, coextensive with Kings County, in the U.S. state of New York. Located at the westernmost end of Long Island and formerly an independent city, Brooklyn shares a land border with the borough and county of Queens. It has several bridge and tunnel connections to the borough of Manhattan, across the East River, and is connected to Staten Island by way of the Verrazzano-Narrows Bridge.

Irish Americans are ethnically Irish people who live in the United States, whether immigrants from Ireland or Americans with full or primarily Irish ancestry.

African Americans, also known as Black Americans and formerly called Afro-Americans, are an American racial and ethnic group who as defined by the United States census, consists of Americans who have ancestry from "any of the Black populations of Africa". African Americans constitute the second largest racial and ethnic group in the U.S. after White Americans. The term "African American" generally denotes descendants of Africans enslaved in the United States. According to annual estimates from the U.S. Census Bureau, as of July 1, 2024, the Black population was estimated at 42,951,595, representing approximately 12.63% of the total U.S. population.

A riot occurred in the Cobble Hill neighborhood of Brooklyn, New York, United States, on August 4, 1862. It involved a group of White Americans, mostly of Irish descent, targeting a group of about 20 Black American workers at a tobacco factory on Sedgwick Street. The New York City Police Department was able to quell the riot with only some minor injuries and property damage.