James Sproat Brown (February 1, 1824 – April 15, 1878) was an American lawyer and Democratic politician from Wisconsin who served in Congress.Brown was born in 1824 in Hampden, Maine. He moved to Cincinnati, Ohio, in 1840 and, after being admitted to the bar in 1843, began practicing law in Milwaukee, Wisconsin, in 1844. Brown was elected prosecuting attorney for Milwaukee County in 1846, and from 1848 to 1850 served as the first attorney general of Wisconsin.