"Monadnock" was then docked for a few months to prepare her for her transfer to California around the tip of South America. The monitor and her escorts departed in late 1865 and reached the Chilean port of Valparaíso in early 1866 where the Americans unsuccessfully attempted to prevent the Spanish from bombarding the undefended town during the Chincha Islands War. The ships reached California in June and "Monadnock" was decommissioned at the end of the month. The monitor was sold for scrap in 1874. The Navy Department evaded the Congressional refusal to order new ships by claiming that the Civil War-era ship was being repaired while building a new monitor of the same name.