When the first settlers arrived in Iowa, nearly 30 of the state's 35 million acres were covered with tallgrass prairie, but in less than 150 years 99.9% of that vast grassland disappeared under the plow. This centuries-old prairie had produced rich, fertile topsoil, yet agriculture cultivation and wind and water erosion seriously depleted it in a short span, with topsoil charted at 14 inches in 1850, 13 inches in 1875, 11.5 inches in 1900, 10 inches in 1925, 8.5 inches in 1950, 7 inches in 1975, and 5.5 inches in 2000. More than 300 native grass and wildflower species had once stretched for endless miles across Iowa, and when Henry Wallace began buying land there, much of Adair was still raw prairie, with bluestem grass standing eight feet tall across much of its twenty-four square miles. Prairie reconstruction on this 9 acres began in 1997 using seed drilled in the spring from Wearin Prairie in Mills County, one of Iowa's few remaining native prairies. Kyle Swanson, vice president of the Henry A. Wallace Country Life Center from 1994 to 1999, helped plan the prairie and was known throughout Iowa for prairie research and restoration projects; after his death on March 13, 2000, he was remembered for his dedication and volunteer work.