An important early event in the community’s history came about in the 1807-1808-09 time period with the building of the Littlestown (Petersburg)-Gettysburg Turnpike. This made Littlestown an important stop for those who drove from Pittsburgh to Baltimore. It was the last stop before entering Maryland. Littlestown was thus a cross-roads town with the Baltimore-Pittsburgh route crossing the Monacacy Road from Frederick to Wrightsville and the Susquehanna River. With the coming of the railroad in 1857 came new lots, two warehouses and a new hotel. The Barker House, a hotel at the northwest corner of King and Queen Streets, had been built in 1848. The population climbed from 394 in 1850 to 702 in 1860. In 1797, it had been reported in the American Gazetter that “Petersburg” had a Catholic Church and about 80 houses.
On June 29, General Kilpatrick’s Division of Union Cavalry bivouacked for the night around Littlestown. Kilpatrick and General George Custer, of Little Big Horn fame, lodged at the Barker House. The next morning, the division of 5000 men took part in the cavalry engagement with 600 Confederates under Jeb Stuart at Hanover. General Pleasanton, commanding the Cavalry Corps of the Army of the Potomac, headquartered at the Barker House, where he received the word that Stuart had been defeated at Hanover. Slocum’s Corps of 13,000 infantry entered Littlestown that evening and was dispatched to Gettysburg the next day. General Sedgewick’s Sixth Army Corps of 15,000 also passed through Littlestown on their way to the Battle. After the Battle, hundreds of wounded soldiers were brought in ambulances from Gettysburg placed on railroad cars at Littlestown. General Daniel E. Sickles, who had lost a leg at Round Top during the Battle of Gettysburg, was among the wounded treated in Littlestown.
It was nearly a century after its establishment that Littlestown was legally recognized with incorporation as a Borough by the Court of Adams County on February 23, 1864. A vote to determine the status of the community had been ordered held on February 28, 1863. Thirty four votes were cast in favor, 28 in opposition of the incorporation. There were 96 freehold residents in the new borough. The first election was held in August of 1864 with W. Frank Crouse elected Burgess (Mayor). Elected as Councilmen were Noah P. Weikert, John Spangler, Sr., David Schwartz, George Stonesifer and Dr. J. S. Kemp. The first official act of the new Council was to borrow $2,000 “for the purpose of procuring volunteers to fill the quota of said Borough”.