Lansford W. Hastings grew up in Mount Vernon, Ohio. In 1842, at the age of 23, he made an expedition to Oregon. He left Independence, Missouri, in May and arrived in Oregon in October. Along the way, Hastings and the other 160 emigrants in his group encountered various problems in getting along with one another, in making steady progress, and in maintaining peace with the American Indian groups they met along the way. The following year, Hastings led a group of emigrants from Oregon to California. His Emigrants' Guide to Oregon and California was published in 1845. Hastings and his book were harshly criticized and Hastings's reputation was ruined forever in 1846 when a group known as the Donner Party followed his advice and took a shortcut that resulted in the deaths of about half the group members. Hastings died in 1870.

Gouverneur Kemble Warren (1830–1882) was born in Cold Spring, New York, and entered the U.S. Military Academy at West Point when he was sixteen. As a member of the Army Corps of Topographical Engineers, Warren went on important survey expeditions to explore trade routes. From 1853 to 1855, Warren assisted in a government study to find the best possible transcontinental railroad route. As part of his study, Warren created the map on page 842—the first detailed map of the United States from coast to coast. Warren also was a successful Union commander during the Civil War.