As the community grew, and more people settled in the area, the citizens formed a political government.

As a community and village grew, it was often called Martinsburg, after Martin West, another nearby land owner.

In 1794, Federal troops passed through and quartered at the town's Barrett Hotel on the way to quell the Whiskey Insurrection.

John Moore, a surveyor, pursuant to the warrant, issued a survey showing 251 acres (1.02 km2) of land.

The Commonwealth of Pennsylvania, through the offices of Governor Thomas Mifflin, issued a patent to Joseph Buldridge for the tract of land known as Hermitage on April 1, 1797.

Joseph Baldridge, another settler that built a mill in the area, was conveyed a deed for a 251-acre (1.02 km2) tract of land known as "Hermitage" in 1797.

The Greensburg-Stoystown Turnpike was constructed along the old Forbes road in 1819, leading to more traffic and prosperity for the borough, which was now the largest town and served as a market place, with taverns, blacksmiths, wagon makers, harness shops and a variety of other merchants, and a post office for the region.

The community continued to grow and on April 2, 1831, the citizens formally formed the borough as a political government.

The Pennsylvania Railroad introduced train service through neighboring Latrobe in 1852, leading to a decline as merchants moved closer to the railway and the Greensburg-Stoystown Turnpike was less frequently used.

The Kingston House, a center for trade and commerce and hotel dating from 1800, was listed in the National Register of Historical Places on June 30, 1983.

1758 Forbes Road was completed 1769 Pennsylvania Government Land Office opened 1794 Whiskey insurrection - Troops were quartered at the Barrett Hotel 1799-1800 Youngstown Borough laid out 1819 Greensburgh-Stoystown Turnpike completed 1831 Youngstown incorporated by Act of Assembly 1852 Completion of the Pennsylvania Railroad through Latrobe 1861 Youngstown was an enlistment center for the Civil War November 9, 1909 Council voted to enter into contract with West Penn Electric Company for placing and maintaining four arc lights on the main street of town.

August, 1818 - Arthur St. Clair, General in the Continental Army, member of the Continental Congress and the 9th President of the United States in Congress Assembled in 1798, the first Governor of the Northwest Territory, the first Commander of the U.S. Army, 1791–92) died in poverty on the Old State Road between Ligonier and Youngstown, when he was riding a wagon into town and probably had a stroke.

Mrs. Mellon authorized funds to purchase many of the things that were auctioned in the 1810 foreclosure sale and had them placed in the parlor and also in the collection of the museum.

[5] According to the United States Census Bureau, the borough has a total area of 0.1 square miles (0.26 km2), all land.

The famed Latrobe Country Club, home course of golfing great Arnold Palmer, lies just outside the southwestern limits of Youngstown.