Robert Porter Patterson Sr. (February 12, 1891 – January 22, 1952) was an American judge who served as Under Secretary of War under President Franklin D. Roosevelt and U.S. Secretary of War under President Harry S. Truman. He was a US circuit judge of the United States Court of Appeals for the Second Circuit after he had been a district judge of the United States District Court for the Southern District of New York. Education and career Born on February 12, 1891, in Glens Falls, New York, the son of Lodice Edna (née Porter) and Charles Robert Patterson, Patterson received an Artium Baccalaureus degree in 1912 from Union College and a Bachelor of Laws in 1915 from Harvard Law School. He entered private practice in New York City from 1915 to 1916, with what today is the law firm of Patterson Belknap Webb & Tyler, also serving with that firm in subsequent periods of private practice. He served in the New York Army National Guard from 1916 to 1917. He served in the United States Army from 1917 to 1919, attaining the rank of Major. He received the Distinguished Service Cross and Silver Star for heroism in France. Patterson served in the 306th Infantry Regiment which was assigned to the 77th Infantry Division. He returned to private practice in New York City from 1919 to 1930. Federal judicial service Patterson was nominated by President Herbert Hoover on April 24, 1930, to a seat on the United States District Court for the Southern District of New York vacated by Judge Thomas D. Thacher. He was confirmed by the United States Senate on May 13, 1930, and received his commission the same day. His service terminated on March 22, 1939, due to his elevation to the Second Circuit. Patterson was nominated by President Franklin D. Roosevelt on February 9, 1939, to a seat on the United States Court of Appeals for the Second Circuit vacated by Judge Martin Thomas Manton. He was confirmed by the Senate on March 20, 1939, and received his commission on March 21, 1939. His service terminated on July 30, 1940, due to his resignation. War Department service Patterson served as a United States Assistant Secretary of War in 1940. He served as United States Under Secretary of War from 1940 to 1945 under Secretary Henry L. Stimson. He was instrumental in the mobilization of the armed forces