Howard Gillihan's Family History

My husband's Gillihan family history goes back to about 1749-1750 in Virginia. We believe they were part of the great Scotch-Irish Immigration in the 18th century but we have not been able to trace them across the ocean. He fought in the Revolutionary War and was wounded in Savannah, GA.
Revolutionary War William, b 1749-50, d 1830; mNancy Walker, Frances Tadlock
William II, b 1804, d abt 1853; m Arena Bush
Rufus Mitchell, b 7-10-1850, d 5-7- 1927; m Mary Wood, Pearl Bennett
William Howard, b 12-7-1882, d 4-20-1966; m Parlee Malone
Jenkins (Red), b 12-16-1909, d 3-29-1975; m Inez Fortner
Howard Glover, b 9-25-1937: m Alice Bojanowski