A member of Virginia's Lee family, he was part of the Fremont Expedition and commanded troops during the Cayuse War in what became the Oregon Territory.
[1] Lee was appointed as one of the peace commissioners, along with Joel Palmer and Robert Newell to seek a truce with the Cayuse and demand they turn over the killers from the massacre at the start of hostilities.
[7] Lee and his troops, with John E. Ross and Joseph Magone as lieutenants, then marched off to The Dalles, arriving on December 21.
[5] Upon arriving there, Lee led his men against a band of Native Americans and drove them off, but not before they stole 300 head of cattle.
After reaching the mission, Gilliam set out for The Dalles with a small force to supply that settlement, before continuing to Oregon City to report to the governor when he was accidentally shot and killed.
That year Lee traveled by ship to New York to acquire inventory for his store, but died of Panama fever on his return to Oregon in 1851.