pursuit of the Mexican Army and was the first to enter Jalapa. While the U.S. Army was stationed at Jalapa, Patterson returned to the U.S. with other volunteer units whose enlistment time had expired. He then resumed his business interests in Pennsylvania, where he acquired 30 cotton mills and became quite wealthy. Patterson became one of the largest mill-owners in the United States and heavily involved in sugar refineries and cotton plantations. He again was an influential figure in Philadelphia politics. Civil War service The American Civil War brought Patterson back to military service. He was appointed major general of Pennsylvania volunteers and commanded the Department of Pennsylvania and the Army of the Shenandoah. In 1861, Winfield Scott, now General-in-Chief of the U.S. Army, gave Patterson vague orders to retake Harpers Ferry. Patterson failed to immediately act on these orders, was outmaneuvered after the Battle of Hoke's Run, and a Confederate army at Winchester, Virginia, under Brig. Gen. Joseph E. Johnston, was able to march without interference to reinforce the Confederates under P.G.T. Beauregard at the First Battle of Bull Run. Johnston did, however, declare that Patterson’s army had largely deterred him from pursuing the shattered and disorganised Union troops as they retreated back to Washington after the battle. Patterson, widely criticized for his failure to contain the enemy forces, was mustered out of the Army in late July 1861. Postbellum life Patterson again returned to his cotton milling business and wrote a book, A Narrative of the Campaign in the Valley of the Shenandoah, in 1861, published in 1865. He was also President of the Aztec Club of 1847 from 1867 to 1881 and was a Companion of the Military Order of the Loyal Legion of the United States. During his tenure as President of the Aztec Club, the Club accomplished what few of its contemporaries did—the successful metamorphosis from a military society to a hereditary one. Patterson was also a trustee of Lafayette College from 1826 to 1835, and president of the trustees from 1876 to 1881. Patterson died in Philadelphia and is buried there in Laurel Hill Cemetery. His son Francis Engle Patterson and his son-in-law John Joseph Abercrombie were both Union generals during the American Civil War. Patterson's mansion was located on the southwest corner of 13th and Locust Streets. After Patterson’s death in 1881, the Historical Society of Pennsylvania purchased the mansion as its permanent