Born near Lexington, Kentucky, Baker moved with his father to Lebanon, Illinois, in 1829.

He studied law and was admitted to the bar in 1846, entering private practice in Belleville, Illinois.

In 1876, he campaigned in Illinois for Rutherford B. Hayes, who rewarded him by appointing him as United States Minister to Venezuela (1878–1881 and 1882–1885).

He died in Belleville on March 1, 1903, and was buried in Walnut Hill Cemetery.

This article incorporates public domain material from the Biographical Directory of the United States Congress