Judge and historian. He was educated privately and sent on horseback to attend the University of Virginia in 1877. In 1883 he was admitted to the Texas Bar Association. In the town of Crockett he served as a school board member from 1890 to 1892, County Judge from 1892 to 1896, member of the 1918 District Exemption Board and the 1936 Texas Centennial Advisory Committee, and chairman of the Democratic Executive Committee from 1926 to 1936. Aldrich was also a representative to the Twenty-seventh Texas Legislature. Austin College in Sherman, where he was a trustee from 1900 to 1930, awarded him an honorary LL.D. on May 31, 1937. He was a Presbyterian elder and Sunday school superintendent. He wrote a weekly history column in the Crockett Courier and wrote "A History of Houston County" in 1943. He was a member of the Knights of Pythias, president of a chapter of the Sons of the Republic of Texas, president of the David Crockett Memorial Association, president of the Houston County bar, and organizer of the David Crockett Building and Loan Association and the Aldrich Abstract Company.