Riker akatadza kutungamira chikwata chake panguva yekufambira mberi kweManassas kutanga kwaKurume 1862, asi akakwanisa kutungamira varume vake gare gare mumwedzi iwoyo kuFort Monroe, pamwe nevamwe vese veArmy of the Potomac, sechikamu cheMcClellan's Peninsula Campaign. Riker akatungamirira chikwata chake muhondo yeWilliamsburg neHondo yeFair Oaks
muna May 1862.