Liberty is a city in Montgomery County, Kansas, United States. As of the 2020 census, the population of the city was 99. Liberty was laid out i…Liberty is a city in Montgomery County, Kansas, United States. As of the 2020 census, the population of the city was 99. Liberty was laid out in 1869 about six miles southeast of Independence, Kansas. It is named for the popular American ideal of liberty. When the railroad was built through the county in 1870, Liberty relocated to its present site. The first post office in Liberty was established in May 1870.