sentences:  The county is named in honor of Colonel Francis Vigo, of Italian heritage but a citizen of Spain due to residence in St. Louis.He is credited with great assistance to George Rogers Clark both in financing Clark's exploration and American Revolutionary War efforts, and in service as an agent obtaining military information for Clark against British campaigns on the then frontier.To the north of Vigo County, the Wabash River defines the boundary between Vermillion and Parke counties; the river then enters Vigo County and winds to the south-southwest, defining the southern portion of the county's western border before continuing south along Sullivan County's western border.