He was the only President of the United States to be born on July 4. He was married to Grace Coolidge and had 2 children: John Calvin Coolidge III (born September 6, 1906 - died May 31, 2000) and John Calvin Jr. (born April 13, 1908 - died July 7, 1924). His younger son John Calvin Coolidge IV died at 16 while playing tennis at the White House. His son was wearing tennis shoes without socks and died from a toe infection. He was buried at the foot of Hill Cemetery. After this, President Coolidge may have been depressed.