Censuses can help. In 1880, Angelo, Monroe, WI, ROBERTS:
David, 46, wf. "Elieweth," 38, they & parents b. Wales. Ch. b. WI:
Ellen, 19; Lizzie, 16; Annie, 14; Davie, 8.
In 1900, Angelo, WI, ROBERTS, David, b. Sep. 1833, Wales, imm. 1854; wf. Lizzie, b. Feb. 1842; m. 42 y. She had 8 ch., only 3 living. David, b. Nov. 1872. (but he was 8 in 1880).

Death record: David ROBERTS, widowed (1830, Wales - 28 Aug. 1904, Angelo, WI).

Do you know whether David had a brother William ROBERTS? David ROBERTS, 23, & Wm. ROBERTS, 20, arrived at Castle Garden, NY, 9 Sep. 1853, on the Colonel Cutts, from Wales via Liverpool [Google Castle Garden].

The marriage record of William ROBERTS, son of William & Elisabeth, 28 Nov. 1857, Sparta, WI, & Martha JONES, d/o Wm. & Sarah, is on Pilot.FamilySearch.org.