The Platte County Court approved this site as the location of the County Seat on December 4, 1839, due to its central location and officially named the site Platte City. The development and first sale of lots began in early 1840. Improvements and construction were rapid; within a few months, there were six stores and 400 inhabitants. Many trades and professions were represented.
Platte City was incorporated as a city in September 1843. The first trustees were W.C. Remington, Phil Lutes, John S. Porter, John Edwards and W.E. Black.
A charter was obtained from the Legislature in 1845 for Platte City. Main Street was graded and sidewalks laid.
The first doctor to locate in Platte City was Dr. Fredrick Marshall.
Church services of the various and existing denominations were held in homes, log cabins, barns, etc., until late 1842. The first Court House was completed and opened for use in December 1842 and the upper floor was seated by subscriptions and all denominations held services there until building and/or organizing privately.
The first church was Methodist, 1848; followed by the Baptist, in 1850; the Christian, in 1855; and the Catholic, in 1870. The Presbyterian had organized in 1843 and shared the Methodist Church Building for services.
Colonel Morgan’s Union Squad burned Platte City in December 1861. Buildings destroyed included the Court House, which was relocated and rebuilt in 1867.
Two colleges were founded in Platte City. The Male Academy in 1851 and it was burned by federal orders in 1864. Professor Todd’s Academy for Girls was founded in 1857. It continued in operation until it closed in 1908. The Academy for Girls had, during its regime been known also, in order, as the Platte City Female Academy, Daughters College and Gaylord Institute.
The first public school building was erected in Platte City in 1868.
The first telephone was connected in 1883 - a connection with Weston. The local exchange was first established in 1897; the first electric lights installed in 1909; and the waterworks and sewage systems in the early 1930's.
The first daily mail service was established in 1870 and statistics indicate that news from Washington D.C. was available within seven or eight days, compared with twenty days in 1843.
Platte City became a fourth Class City in 1882 and elected as its first Mayor John L. Carmack. The population was 411 in 1850; 670 in 1880; 706 in 1890 and 2940 in the 1990, 3866 in the 2000 census, and 4691 in the 2010 census