During his lifetime, the Prebysterian minister reportedly traveled more than a million miles to spread the Christian gospel, founding churches and missions nationwide along the way. But he spent the later part of his life exploring the vast territory that would later become Alaska. In 1885, the U.S. government appointed him the region's first-ever education superintendent, tasking him with setting up free public schools for Native American, Eskimo, and white children. Jackson also introduced reindeer to the area, importing the animals from Siberia in 1892 as an alternative meat source (cattle and other animals cannot survive the frigid winters) amid fears of famine.