Rosamond is an unincorporated community in Rosamond Township, Christian County, Illinois, United States. It lies at 39°22′48″N 89°09′43″W / 39.380°N 89.162°W. The earliest known local resident was Capt. Alfred Cowgill who settled in the area in 1856. Cowgill moved to Assumption for a few years, returning to Rosamond where he worked for grain dealer …Rosamond is an unincorporated community in Rosamond Township, Christian County, Illinois, United States. It lies at 39°22′48″N 89°09′43″W / 39.380°N 89.162°W. The earliest known local resident was Capt. Alfred Cowgill who settled in the area in 1856. Cowgill moved to Assumption for a few years, returning to Rosamond where he worked for grain dealer S.M. Hawood & Son. After moving to Montrose, Mo., he returned to Rosamond and worked for Hawood & Son until 1878.