Williams was born on January 3, 1787, on Horse Creek, a branch of the Pacolet River, under Skyuka Mountain in Polk County, North Carolina, into a Welsh family.

[1] Williams was a master fur trapper and trail guide, becoming fluent in several Native American languages among the tribes he knew the best.

[6] Williams married A-Ci'n-Ga, a full-blood Osage woman whose name translates to "Wind Blossom",[b] circa 1813.

[13] Biographer Alpheus Hoyt Favour notes that it is hard to distinguish myth from fact between the years of 1825 and 1841 in Williams life.

[14] He definitely traveled the Southwestern United States and may have married a Spanish woman and had a child, but Favour notes there is scant evidence.

[1] Other members of the expedition included Benjamin Bonneville, Joseph Meek, Alexis Godey, Antoine Janis, William Craig, George Nidever, and Zenas Leonard.

[1] Historian Michael Snyder, an Oklahoma State University professor and Osage Nation citizen, noted Williams's reputation declined as he aged.

[18] In November 1848, John C. Fremont hired Williams to guide his ill-fated fourth expedition through the Southern Rocky Mountains.

[21] Williams led a rescue party south towards Taos, and the survivors of the expedition eventually managed to follow.

[22] In March, Williams and Dr. Benjamin Kern returned to the La Garita Mountains in hopes of finding more survivors.