Joel Palmer was born October 4, 1810 in Elizabethtown, Ontario (Canada) to Ephraim and Anna Palmer. When Joel was two his family fled the ravages of the War of 1812 and settled in the frontier village of Lowville in northern New York. At twelve years of age Joel was "bound out" (a form of indentured servitude) to the Haworth family in the Catskill Mountains. In 1826 at age 16 he left the Catskills for Philadelphia; there he married Catherine Caffee in 1830, who died giving birth to their daughter. In 1836 he married Sarah Anne Derbyshire and moved to Laurel, Indiana, where he worked as a canal-building contractor. In 1843 Palmer was elected to the Indiana state legislature, representing Franklin County as a Democrat. He won a second term in 1844.

In April 1845 Palmer visited Oregon, which was not yet a territory; he recounts the trip in his Journal of Travels Over the Rocky Mountains. In 1847 he brought his wife and children to Oregon to settle permanently. That winter the Cayuse War broke out, and Palmer was chosen to be the commissary general of the volunteer fighting force. Within weeks he was also appointed Superintendent of Indian Affairs for the provisional government, and became one of three men serving on the Peace Commission.

In 1848 Palmer joined the Gold Rush to California. He returned the next year and encouraged the growth of the town of Dayton, planting orchards and helping to build a sawmill. In 1853 he was appointed Superintendent of Indian Affairs, now serving the officially recognized government of the Oregon Territory. He negotiated nine treaties between 1854 and 1855, and helped settle difficulties during the Yakima Indian War. However, Palmer's tolerant treatment of Indians and his attempts to restrain settler activities led to campaigns against him, and in 1857 he was removed from office.

Palmer spent the last twenty years of his life pursuing a variety of mostly failed business ventures. He remained active in politics, and became speaker of Oregon's house of representatives in 1862. In 1864 he was elected to the state senate, and declined to serve again in 1866. In 1870 he was defeated as Republican candidate for governor, but in 1871 he accepted a post as Indian agent at Siletz, from which he resigned in 1873. General Joel Palmer died on June 9, 1881; he was survived by his wife Sarah and their eight children.