Rev William Mumford Baker (1825–1883) was the youngest son of Daniel Baker (1791-1857), the great evangelist of the American South. He graduated from Princeton Theological Seminary in 1848. He was ordained an evangelist by the Presbytery of Little Rock on April 22, 1849, and for a short time served as minister at the Presbyterian church in Batesville, Arkansas. In 1850, Baker became the first pastor of the Presbyterian Church in Austin, Texas.
A unionist, Baker and his family moved north at the close of the Civil War, serving churches in Zanesville, Ohio (1866-72), Newburyport, Massachusetts (1872-74), and Boston, Massachusetts (1874-76).
From 1877 to 1881 he resided in Boston and concentrated on his writing. He prepared the biography of his father Making Many Glad: The Life and Labours of Daniel Baker, published by the Trust.
Baker died on August 20, 1883, after a two-year illness, and his body was transported back to Austin for burial beside his father in Oakwood Cemetery.