What is USA's oldest intercollegiate sports event held between Yale and Harvard?

The Harvard-Yale Regatta or Yale-Harvard Boat Race (often abbreviated The Race) is an annual rowing race between the men's heavyweight rowing crews of Harvard University and Yale University. First contested in 1852, it has been held annually since 1859 except during major wars fought by the United States. The Race is America's oldest collegiate athletic competition. It is sometimes referred to as the "Yale-Harvard" regatta, though most official regatta programs brand it "Harvard-Yale."

Originally rowed on Lake Winnipesaukee, New Hampshire, it has since moved to the Thames River, near New London, Connecticut. Although other locations for the race have included the Connecticut River at Springfield, Massachusetts, and Lake Quinsigamond at Worcester, Massachusetts, the Thames has hosted The Race on all but five occasions since 1878 and both teams have erected permanent training camps on the Thames at Gales Ferry for Yale and at Red Top for Harvard.

The race has been exclusively between Yale and Harvard except for 1897 when the race was held as part of a three-boat race with Cornell on the Hudson River at Poughkeepsie, New York, where, although it lost to Cornell, Yale was deemed the winner of the Harvard-Yale race.