Keswick is a city in Keokuk County, Iowa, United States. The population was 242 at the time of the 2020 census. The Burlington, Cedar Rapid…Keswick is a city in Keokuk County, Iowa, United States. The population was 242 at the time of the 2020 census. The Burlington, Cedar Rapids and Northern Railway built a 66-mile branch to What Cheer via Keswick in 1879 The town is named for Keswick, England, the home town of a local woman who had offered lodging to the track-laying crew.