He emigrated to the United States with his mother and sister. On the ship record he is listed as Richard Gibson. His mother changed his name to William Moroni when he was baptized shortly before they set sail. However, he is listed as Robert on the ship's register.

His mother died in Illinois in 1860. Shortly thereafter, his aunt, Mary Ann Gibson Perkes, became his and his sister's guardian. The Perpetual Emigrating Fund Ledger shows him and his sister bonded to James and Mary Perkes.