Marshall County was located on the Oregon Trail, the Mormon Trail, and the route of the Pony Express. The Holladay stage line from Atchison to Salt Lake City also passed through here. Frank J. Marshall established a trading post and a ferry across the Big Blue River at a site which he named Marysville for his wife. Marshall was a proslavery candidate for governor in 1857.
The Oregon Trail crossed the Blue River about 6 miles south of Marysville. The Donner party came through there in 1846 and named a spot near their campsite Alcove Spring. Today this site is considered one of the most important Oregon Trail sites in Kansas.
Two Pony Express stations were located in Marshall County. At Marysville the original 1859 pony barn is now a museum. Guittard Station near Beattie is commemorated by a roadside marker.
William G. Cutler's History of Kansas, first published in 1883, tells about early Marshall County.
There is a section on Marshall County in the book Kansas: a Cyclopedia Of State History by Frank Blackmar (1912).
The Special Collections of the Ablah Library at WSU contain historical images of Marshall County towns: Axtell, Beattie, Bigelow, Blue Rapids, Bremen, Frankfort, Herkimer, Home, Irving, Marysville, Summerfield, Vermillion, and Waterville.
The Kansas State Historical Society also has more historical data for Marshall County online including a rich bibliography and lists of cemeteries, post offices, and newspapers.