Augusta Van and Adeline Van Buren
Because life is often stupid and unfair, the most famous pair of motorcycle-riding siblings in American history are probably Billy and Benny McCrary, the morbidly obese twins who gained fame thanks to the Guinness Book of World Records. While those clowns got all the glory, America's Badassinest Motorcycle-Riding Siblings were unquestionably Augusta (L) and Adeline Van Buren (R).
In 1916, with America inching closer to entering the fray in Europe, Gussie, 24, and Addie, 22, were big into the Preparedness Movement. Eager to prove that women could take a much more active role in the war effort by serving as dispatch riders, the sisters resolved to drive across county on their motorcycles.
On the Fourth of July, 1916, the sisters each hopped astride 1,000cc Indian Power Plus bikes, setting off from from Sheepshead Bay Race Track in Brooklyn. On September 8, sixty days, 5,500 miles, and a few threats of arrest (for wearing trousers) later, they arrived in Los Angeles. Despite having traversed a continent, the US military rejected their applications out of hand. Dicks.
The military's indifference slowed the sisters not at all, with Gussie becoming a pilot and joining Amelia Earhart's Ninety-Nines, and Addie earning her JD from NYU.
In 2002, the sisters were posthumously inducted into the American Motorcycle Hall of Fame, and in 2016, several of their descendants led a group of 66 others, with the backing of Indian Motorcycles, in a centennial trip retracing of the Van Buren's original ride.