I have done a lot of research on the Alt/Ault families of Virginia and I believe I know how your William ties in.
On the U.S. Civil War Draft Registration Records 1863 - 1865, Muskingum Co. Ohio, Adams twp. William Ault age 41 Farmer b. Virginia.
The 1880 census lists him as born in Virginia and his father & mother b. in Virginia.
I believe he was Wilhelm Alt b. Nov 20, 1820 Loudoun Co. VA, bapt. Apr. 22, 1821 at the New Jerusalem Church, Lovettsville, Loudoun Co. VA. He was the son of Johannes/John Alt b. Oct 20, 1792 Loudoun Co. VA and Maria Juliana Spring.
John Alt/Ault, his father moved to Muskingum Co. Ohio before 1840. He is on the census there in 1840 and later census records.
I can give you more information on the Alt ancestry if you want.