The Three Sisters are part of the Fall Line, a geologic feature which distinguishes the sedimentary coastal plain of the mid-Atlantic region of the United States from the basement rock of the inland.

Georgetown, which preceded the establishment of the District of Columbia, was the furthest point inland that shipping vessels could reliably reach when coming up from the Atlantic Ocean.

One of the earliest stories involves three Algonquian sisters who crossed the river in an attempt to win the release of their brothers, who had been kidnapped by another tribe.

[10][11] A less commonly cited legend says three daughters of the local Native American chief were marooned on the islands by their father after rejecting the husbands he picked out for them.

[17] The idea for a large George Washington Memorial Parkway came from Representative Louis C. Cramton, who introduced legislation in January 1929 to construct a larger system of roads and parks.

The act appropriated $13.5 million to acquire land and build a parkway on the Virginia shoreline from Mount Vernon to the Great Falls of the Potomac (excluding the city of Alexandria), and to build a parkway on the Maryland shoreline from Fort Washington, Maryland, to the Great Falls of the Potomac (excluding the District of Columbia).

In mid-1961, the District of Columbia Department of Transportation proposed constructing a six-lane, 160-foot-wide (49 m) bridge linking the Virginia and D.C. segments of the George Washington Memorial Parkway at the Three Sisters.

[24] Finally, in December 1971, Representative Robert Giaimo led a successful revolt on the House floor which restored the Metro funding over Natcher's vehement opposition.

[25] The islets are integral to the plot of Breena Clarke's best-selling novel River, Cross My Heart, set in the Georgetown neighborhood of Washington, D.C., in 1925.

[26] A false legend about the landmark (that three nuns drowned at the Three Sisters, giving the rocks their name) is given in River, Cross My Heart, and also by David Baldacci in his novel The Camel Club.