County, Indiana Madison County, Iowa Madison County, Kentucky Madison County, Mississippi Madison County, Missouri Madison County, Montana: named for the Madison River, named in turn for James Madison Madison County, Nebraska: probably named for Madison, Wisconsin, where most of the new county's settlers were from, named for James Madison Madison County, New York Madison County, North Carolina Madison County, Ohio Madison County, Tennessee Madison County, Texas Madison County, Virginia Madison Parish, Louisiana Clay County (18 counties) Fifteen of the eighteen Clay Counties in the United States are named for Henry Clay, the Kentucky statesman. Two of the exceptions, including one in Kentucky, are named for members of Henry Clay's family. Clay County, Alabama Clay County, Arkansas: named for John Clayton, a member of the Arkansas Senate Clay County, Florida Clay County, Georgia Clay County, Illinois Clay County, Indiana Clay County, Iowa: named for Henry Clay's son, Henry Clay, Jr., a general who died during the Mexican–American War Clay County, Kansas Clay County, Kentucky: named for Henry Clay's cousin, Green Clay, a general in the War of 1812 Clay County, Minnesota Clay County, Mississippi Clay County, Missouri Clay County, Nebraska Clay County, North Carolina Clay County, South Dakota Clay County, Tennessee Clay County, Texas Clay County, West Virginia Greene County and variants (17 counties) All Greene Counties in the United States are named after Nathanael Greene, a major general in the Continental Army during the American Revolutionary War. Greene County, Alabama Greene County, Arkansas Greene County, Georgia Greene County, Illinois Greene County, Indiana Greene County, Iowa Greene County, Mississippi Greene County, Missouri Greene County, New York Greene County, North Carolina Greene County, Ohio Greene County, Pennsylvania Greene County, Tennessee Greene County, Virginia Two Green Counties, despite the difference in spelling, are also named after the aforementioned Nathanael Greene. Green County, Kentucky Green County, Wisconsin One other county may have been named after Greene, although there is evidence that it was instead named for Richard Grenville, leader of the settlement on Roanoke Island. Greensville County, Virginia Montgomery County (18 counties) Most (at least 13 out of 18) Montgomery Counties in the United States are named after Richard Montgomery, a major general in the Continental Army killed in the 1775 Battle of Quebec. Montgomery County, Alabama (This county was not named for Richard Montgomery, but for another general, Lemuel P. Montgomery; oddly, the city of Montgomery, Alabama in it was named for Richard