John Charles Frémont (1813 –1890) was an American military officer, explorer, senator from California, and first candidate of the Republican Party for President of the United States. The edition covers four expeditions made by Fremont, who became known popularly as The Pathfinder. This is a selective edition of the personal and public papers and correspondence about the expeditions, including a portfolio of maps, and the Bear Flag Revolt and court-martial proceedings. The map portfolio is online at https://www.ideals.illinois.edu/bitstream/handle/2142/9074/expeditionsofjoh00fr.pdf