During the American Civil War, Cook served with Terry's Texas Rangers and attained the rank of colonel.
[1] He contested the 1872 Texas legislative election, and was awarded the seat held by Richard Allen.
[1][2] Later that year, Cook was appointed to a criminal court judgeship representing Harris and Galveston County, Texas.
Cook attended the Philadelphia Peace Convention of 1866 to represent Texas, and ten years later, served as a delegate to the Democratic Party's state convention, held in the city of Galveston.
The party's eventual nominee, Jim Hogg, won the governorship.