Mount Vernon was laid out in 1847, but its origins date back to at least 1838, when it was known as Pinhook, a popular rest stop on Military Road, which ran between Dubuque, on the Mississippi River, and Iowa City. It was renamed Mount Vernon in 1847, after the estate of George Washington. A post office has been in operation in Mount Vernon since 1849. The Iowa Conference Male and Female Seminary (which later became Cornell College) was established in the town in 1853, and the Northwestern Railroad reached it in 1859, bringing new business to the town as its population expanded.
Mount Vernon is located at According to the United States Census Bureau, the city has a total area of 3.50 square miles (9.06 km2), of which, 3.49 square miles (9.04 km2) is land and 0.01 square miles (0.03 km2) is water.(41.924096, -91.419679).
The central geographic feature of Mount Vernon is the "mountain" on which it sits. This "mountain" is actually a paha, a ridge formed of sand and loess along the line of the prevailing wind during the ice ages. The Mount Vernon paha is roughly one mile (2 km) long and 1/4 mile (1/2 km) wide, aligned along a roughly northwest to southeast axis and standing up to 100 feet (30 m) above the surrounding landscape. Uptown Mount Vernon is aligned with the southeast end of the ridge crest, while the campus of Cornell College crowns the northwest end of the ridge.
The town is located on significant transportation corridors, both current and historical. The main line of the Union Pacific Railroad passes through the city, and the town is located on the historic Lincoln Highway. U.S. Route 30 and Iowa Highway 1 intersect in the southern part of town. Passenger train service was once provided by the Chicago and North Western Railway from a station in the north of town. The CRANDIC interurban electric railway ran from Cedar Rapids, through downtown Mount Vernon, and ended in nearby Lisbon. The interurban ran from 1914 to 1928 and took 45 minutes to travel to the western terminus of Cedar Rapids. Nearby stops included Bertram, the Palisades and Cornell College.
As of the census of 2010, there were 4,506 people, 1,353 households, and 894 families residing in the city. The population density was 1,291.1 inhabitants per square mile (498.5/km2). There were 1,397 housing units at an average density of 400.3 per square mile (154.6/km2). The racial makeup of the city was 95.0% White, 0.9% African American, 0.2% Native American, 1.7% Asian, 0.5% from other races, and 1.6% from two or more races. Hispanic or Latino of any race were 1.9% of the population.