Over 360,000 Pennsylvanians served in the Union Army, more than any other Northern state except New York. (Other states sent larger proportions of their population, but not larger numbers.) Beginning with President Lincoln's first call for troops and continuing throughout the war, Pennsylvania mustered 215 infantry regiments, as well as dozens of emergency militia regiments that were raised to repel threatened invasions in 1862 and 1863 by the Confederate States Army. Twenty-two cavalry regiments were also mustered, as well as dozens of light artillery batteries.