From August 15 to August 29, 1862 Ruggles was in command of the Port Hudson position on the Mississippi in Louisiana and supervised the planning and initial construction of fortifications in that region. On the 29th he was ordered by Breckinridge to move with some of his troops to the state of Mississippi to aid Earl Van Dorn in his attempt to recapture Corinth, Mississippi in the ensuing Second Battle of Corinth.