An early settler, Andrew P. Williams, donated sixty acres of land and the town was laid out in the fall of 1833.

Richardson the task of selecting lots upon which to build the courthouse, county jail, a schoolhouse, and church.

The streets of the new county seat were also to be named, with those running north to south being Decatur, Jackson, Perry, Washington, and Water, while the east-west cross streets were christened Benton Clay, Greene, Jefferson, and Lafayette.

[6] Despite the North Fabius being navigable only by rafts, flatboats, and assorted small craft Monticello at first did a thriving business as a supply point for central and western Lewis County, as well as portions of neighboring Knox and Scotland counties.

[8] The Monticello area, like much of Lewis County, was pro-Confederate during the American Civil War.

With the outbreak of the Civil War and a riot at Canton on July 4, 1861, Judge Green called on Lewis County's pro-Confederate citizens to assemble under the banner of the Missouri State Guard at a training camp on the Fabius River at "Horseshoe Bend" not far from Monticello.

A few weeks later Green's forces would be defeated by pro-Union Missouri Home Guards at the Battle of Athens in neighboring Clark county.

Green would rise to the rank of Confederate Brigadier General before being killed at the Siege of Vicksburg in late June 1863.

On July 9, 1862, Confederate guerrilla leader Raphael Smith, a pre-war tanner in the area, raided Monticello with a force of eighty men.

[9] There they captured or "liberated" various supplies and forced one the towns ardent Union supporters to take an oath of allegiance to the Confederacy.

Smith's group would again attempt to raid Monticello a few weeks later on September 1, but were driven off by the approach of a 300-man Union cavalry patrol.

Rail lines fostered better trade and allowed for towns such as Durham, Ewing, La Belle, and Lewistown to thrive and outgrow Monticello.

In both newspaper articles and public meetings, residents of Canton, La Grange, and Lewistown all attempted to sway the county government.

[6] However, the efforts of all three towns were in vain and no real challenge to Monticello as the county seat would happen again despite its dwindling population.

[10] According to the United States Census Bureau, the village has a total area of 0.26 square miles (0.67 km2), all land.