Practical advice for making your union last, from people who know: couples whose relationships have stood the test of time.

What would Barbara do for love? Take two years of summer-school classes if it meant graduating at the same time as high school sweetheart Morgan, who was two years older. The Bellevue, Washington-based pair, who wed when Barbara was 20 and have six grandchildren, are still very much in love. “But to us that doesn’t mean being joined at the hip,” says Barbara, 73. An avowed night owl, she stays up until 2 A.M. reading mysteries, while Morgan, 75, goes to bed early and rises at 4:30 to work out at the gym.

Photograph by Gillian Laub