Robert Todd Lincoln (August 1, 1843 – July 26, 1926) was an American politician, lawyer, and businessman. The first son of President Abraham Lincoln and Mary Todd Lincoln, he was born in Springfield, Illinois, and graduated from Harvard College before serving on the staff of Ulysses S. Grant as a captain in the Union Army in the closing days of the American Civil War. After the war Lincoln married Mary Eunice Harlan, and they had three children together. Following completion of law school in Chicago, he built a successful law practice, and became wealthy representing corporate clients.