He was 10 when he watched his first Kentucky Derby in 1934, the midst of the Great Depression, hoisted on his father’s shoulders near the finish line on the clubhouse lawn at Churchill Downs. On Saturday, William Camp Jr. will attend his 75th Kentucky Derby after having missed just two since 1938 – one because he was serving in the Army in Germany during World War II and the other so he could pass final exams at the University of Virginia.