There's more than one place called '''Monmouth''':
Monmouth (Wales) - a town in Gwent, South Wales
Monmouthshire (a historic county) - see the Gwent article
Monmouth (Illinois) - a town in Warren County, Illinois
Monmouth (Maine) - a town in Kennebec County, Kennebec and Moose River Valleys, Maine
Monmouth (Oregon) - a city in Polk County, Oregon
Monmouth County - in the Shore (New Jersey) region of New Jersey