This fine group of Federal-style houses was built in 1805 by Col. John Cox, Georgetown's first mayor elected by popular vote - an office he held for 22 years. No 3339 was Cox's residence for a time, and in 1824 he entertained the Marquis de Lafayette at no 3337. In 1957 John F. Kennedy, senator at the time, purchased no 3307 and lived there with his wife until they moved into the White House.