Sgt. James Capper, Nelson Henry Tucker families of RI

I am seeking the origins of Sgt. James Capper, born 1838 in Rhode Island.He served in Co. C, 3rd RI Regiment of Heavy Artillary in the Civil War.He settled in Little Falls township, Monroe County WI, and married Frances M. (possibly Berry), born 1840, died 1915.James died in 1966 and is buried in Burns Cemetery (La Crosse county).
A daughter, Alice I. Capper was born 1859 and died 1931.Alice married Nelson Henry Tucker, born 1851 in South Kingston RI.He died 1942 in WI.Nelson and Alice are my husband's greatgrandparents.We have Nelson's line, but have no clue on the Capper family.I would be willing to share information and have tombstone photos of many Cappers and Tuckers, also some Berrys.
Linda