 mercer county is a county located in the northwestern portion of the u.s. state of missouri. as of the 2010 census, the population was 3,785, making it the second-least populous county in missouri. its county seat is princeton. the county was organized february 14, 1845 and named for general john f. mercer of the revolutionary war. ==history== ===early years=== mercer county was organized february 14, 1845, from part of grundy county, missouri.missouri secretary of state, missouri history: what are the origins of missouri counties? it is named in honor of general john francis mercer who fought and died in the american revolutionary war. the first permanent settlements in what is now mercer county were in 1837 when a few families from other parts of missouri moved to the area. james parsons, a tennessee native, is generally considered to be the first permanent settler in the spring of 1837.a directory of towns, villages and hamlets of mercer county, missouri by arthur paul mosler. the land was still included as part of livingston county at that time and would remain so until 1841 when it would become part of the newly created grundy county. prior to 1837, the land was used by native american tribes, primarily the sac/fox and potawatomi, as prime hunting grounds. the occasional temporary hunting village would be established by the tribes but otherwise the land was devoid of humans. the town of princeton, named for the battle where general mercer was killed, was established as the county seat in 1847.encyclopedia of the history of missouri, edited by howard l. conard vol. iv, pages 327-328. published 1901 the northern boundary of the county was in dispute for the first six years of its existence due to the honey war, a bloodless territorial dispute between missouri an
1845_establishments_in_Missouri Missouri_counties Populated_places_established_in_1845