This thesis analyzes the political career of Oran M. Roberts during the critical period from 1850 to 1873. Through a reassessment of Roberts's extensive personal papers in the context of modern historical scholarship, the author explains how Roberts's political philosophy reflected the biases and prejudices typical of his era, as well as his own material interests and ambitions. Topic areas covered include Roberts's position on the Compromise of 1850, his constitutional philosophy, his involvement in the secession movement in Texas (including his service as president of the state secession convention), his military career during the Civil War, his participation in Presidential Reconstruction, his views on Congressional Reconstruction, and his role in the process of "redemption" in Texas.