Kentucky
"The Bluegrass State" became the 15th state on June 1, 1792.
Kentucky's major mineral resources are coal, oil, clay and natural gas. The great coal fields of Kentucky are in the mountains. And even though they have been some of the nation's largest producers of coal, it is estimated that there are at least 33,000,000,000 ...yes, billion...tons of coal still unmined. Kentucky also produces cement, clay, sand and gravel, lime, and Fluorspar.