109th Infantry Regiment (United States)  The 109th Infantry Regiment ("Thirteenth Pennsylvania") is a parent infantry regiment of the United States Army, represented in the Pennsylvania Army National Guard by the 1st Battalion, 109th Infantry, part of the 2nd Brigade Combat Team, 28th Infantry Division. Headquartered at Scranton for the duration of its existence, the regiment was formed as the Scranton City Guards Battalion of the Pennsylvania National Guard in 1877, and expanded into the 13th Infantry Regiment, Pennsylvania National Guard a year later. It was called up for the Spanish–American War as the 13th Pennsylvania Volunteer Infantry Regiment, but did not serve overseas, and again to guard the Mexican border in 1916. The 13th combined with another Pennsylvania regiment to form the new 109th Infantry in 1917 for service in World War I with the 28th Division. Demobilized after the end of World War I, the 13th Infantry was briefly reorganized in the Pennsylvania National Guard before regaining its World War I designation in 1921, part of the reorganized 28th Division. As a result of World War II, it was again mobilized with the division in early 1941. After the end of the war, the 109th was reorganized at Scranton in 1946, being called up as a result of the Korean War to replace Regular Army units sent to Korea. The 109th was organized on 14 August 1877 as the Scranton City Guards Battalion, a unit of the Pennsylvania National Guard based at Scranton. On 23 September 1878, it was expanded, reorganized, and redesignated to become the 13th Infantry Regiment. By 1898, it included eight companies: A, B, C, D, F, and H at Scranton, E at Honesdale, and G at Montrose. The regiment formed part of the Third Brigade of the Pennsylvania National Guard division. In response to President William McKinley's proclamation calling for volunteers to serve in the Spanish–American War, the regiment encamped at Mount Gretna on 28 April, where it joined the rest of the Pennsylvania National Guard to be mustered into Federal service. At Mount Gretna, it accepted recruits to increase the strength of each company to three officers and 75 men. All companies except for Company A and the regimental headquarters were mustered into Federal service on 12 May, followed by the latter on the next day. In Federal service, the regiment was designated the 13th Pennsylvania Volunteer Infantry Regiment. The 13th Pennsylvania departed Mount Gretna for Camp Alger in northern Virginia on 19 May and arrived there the next day.