During their years in the White House, President Adams and his wife Louisa seldom spent much time together. Except for breakfast and an occasional dinner, during which they both read papers and rarely talked, they often went for weeks without much communication. And by his second year in office, they began taking separate summer vacations. For John Quincy Adams, regularity in life was lifted to obsession. He wrote in his diary every day from his twenty-ninth birthday until his death. As President, he rose precisely at five A.M. (4:15 in the summers), made his own fire, read his Bible, and then took a morning walk or a swim in the Potomac. His biographer, Paul C. Nagel, reports one notable instance when, while swimming, Adams and his manservant found an old boat tied at the bank. Adams suggested that they row across the river and swim back. Halfway across, the boat capsized and the men jumped overboard, losing their clothing. The servant donned soaked garments and returned to shore for help. Adams, unclad, sat on a rock to wait. Five hours passed before the servant came back. Afterward, Louisa scolded him, and Adams's physician advised less hazardous exercise, but the swimming continued, only somewhat moderated by John Quincy's developing interest in botanical research in the White House gardens.

Besides swimming, Adams enjoyed shooting billiards (he installed the first billiard table in the White House), reading, observing nature, domesticating wild plants, walking, horseback riding, attending the theater, and partaking of fine wines. He hosted wine samplings and prided himself on his ability to identify rare spirits.

Perhaps one of the most cultivated and educated men to serve as President, Adams was not especially religious. He formally joined the Unitarian branch of the Congregational Church once he took office, and he attended church every Sunday. But he questioned the divinity of Christ, the virginity of Mary, and the Bible as divine revelation. For him, Christ was a savior sent by a supreme being to preach peace on earth and the natural equality of all mankind.