The earliest European settlers came to the area in the 1730s. They were mostly Scotch-Irish who came to America to escape famine in Ireland. In the early days, parts of what are now Adams and York Counties were claimed by both Maryland and Pennsylvania. One such area was "Carroll's Delight," which was chartered in 1735 by Maryland, and covered 5,000 acres in the vicinity of Fairfield and Hamiltonban. The Pennsylvania Provincial Assembly created York County in 1749, which included all of what is now Adams County. The 1749 charter created "Hamilton's Bann" township, which then covered what are now Hamiltonban, Liberty and Freedom Townships as well as Fairfield and Carroll Valley Boroughs.
The early years were difficult for the settlers, especially during the war between the British and French for control of North America (The French and Indian War of 1756-1763). Most of the local indians sided with the French, and the early Pennsylvaina settlers in frontier areas like Hamiltonban were repeatedly raided by the indians, and much bloodshed resulted. After the war, most of the indians retreated westward, and the area was calm again, although still in dispute by Pennsylvania and Maryland until ownership was finally settled in 1767 with the surveying of the Mason-Dixon line. By that time, people of German descent were settling in the area, and they came to dominate local politics before 1800.
The largest settlement in Hamiltonban, Fairfield, was laid out on 247 acres of land in Carroll's Delight purchased by John Miller in 1755. Squire Miller quickly sold off lots for the purpose of agriculture, and built a stone manor house in 1757, and licensed it as a tavern in 1786. His stone house, now called the Fairfield Inn, is still in use as a tavern. In 1800, Adams County was formed from York County and Hamiltonban Township became part of Adams County. In 1801, William Miller, John Miller's son, had his land surveyed and platted for a town to be known as Millerstown. When it was learned that a town by that name already existed, the name was changed to Fairfield.
Throughout the nineteenth century, Fairfield was part of Hamiltonban Township. By far the most traumatic event of this century in Adams County was the Battle of Gettysburg which took place during the Civil War (1861-1865). It was the most deadly battle ever to take place on American soil. This ultimate and decisive confrontation between North and South, and between two ways of life, marked the high water mark of the Confederate tide. Located just south of the focal point of the battle, Fairfield most definately felt the reverberations.
Early in the day on July 3rd, 1863, Jones' Brigade of Stewart's Cavalry Division of the Confederate Army of Northern Virginia fought a bloody battle with the 6th U.S. Cavalry on Carroll's Tract Road, just 2 miles north of Fairfield. The Union Cavalry was driven back to Emmitsburg, and Jones' Brigade remained in Fairfield, protecting the left flank of the Confederate Army during Pickett's Charge on the decisive day of the Battle of Gettysburg. Jones Brigade encamped at Fairfield that night, and the next day, one of two major columns of the Army of Northern Virginia began its retreat through Fairfield, up Iron Springs Road, and over South Mountain through Monterey Gap (now within Borough of Blue Ridge Summit). The other column, with Lee's wagons, supplies, and wounded retreated through Cashtown towards Chambersburg.
In 1896, Fairfield was incorporated as a borough, with it's own governing body separate from Hamiltonban. Carroll Valley Borough was chartered from Hamiltonban and Liberty Townships on September 30, 1974.
For a more thorough discussion of Hamiltonban's history, see the following: