Plattsmouth is a city in and the county seat of Cass County, Nebraska, United States. The population was 6,620 at the 2020 census.
The Plattsmouth Main Street Historic District is listed in the National Register of Historic Places. At upper right is the clock tower of the Cass County Courthouse.
A crowd gathered in Plattsmouth during President William Howard Taft's 1908 campaign visit.
Plattsmouth bridges on June 22, 2011, during the 2011 Missouri River floods
Downtown Plattsmouth looking west along Main Street (2009).
Cass County is a county in the U.S. state of Nebraska. As of the 2020 census, the population was 26,598. and was estimated to be 27,657 in 2025. The county seat and the largest city is Plattsmouth.
The Cass County Courthouse in Plattsmouth