The national wagon road guide, from St. Joseph and Council Bluffs, on the Missouri River, via South Pass of the Rocky Mountains, to California

William Wadsworth made several trips across the plains. His book was considered one of the most useful of the overland guides available beginning in the 1840s. He based his writings on his own observations and experiences and included information from other sources. It contains "a minute description of the entire route" from Missouri to California "with all its branches and cut-offs; distances from place to place; lakes, springs, creeks, rivers, ferries and fording places; mountains, canons, deserts, alkali lagoons, meadows, camping and recruiting places; birds, animals, insects and reptiles; natural phenomena and remarkable scenery; with a map of the route, including the Salt Lake country"