The Brooklyn Times-Union was launched in 1848 as the Williamsburgh Daily Times. It became the Brooklyn Daily Times when the cities of Brooklyn and Williamsburg were unified in 1855. The newspaper supported the Republican Party, and the Abolition movement. Walt Whitman was one of their reporters, and was later the managing editor after he left the Brooklyn Daily Eagle.
The paper was published both daily and on Sunday, and had a peak circulation that included all of Kings County, and large segments of Nassau and Suffolk Counties. As the Brooklyn Daily Times, the paper was published in various editions, including the Long Island, Wall Street, and Noon editions.