Bloomfield Township was formed on 08 December 1876 out of the western half of Middle Woodberry Township.
Bedford and Barre Townships had been formed within Cumberland County in 1767. In 1771, when Bedford County was erected out of Cumberland, Bedford and Barre retained their names and physical boundaries. Four years later, coinciding with the beginnings of the American Revolutionary War in 1775, a new township was formed primarily out of the western arm of Barre, but also from the northernmost part of Bedford. The new township's name was Frankstown, bestowed in honor of Stephen Franks, and his trading post located to the east of present-day Hollidaysburg in Blair County. At the time that it was formed, Frankstown Township encompassed the region between the Allegheny Mountain range on the west and the Tussey Mountain on the east. It stretched from the point where Evitts Mountain merges with Dunnings Mountain in the south to the southern end of Bald Eagle Mountain in the north ~ with the long Dunnings Mountain dividing it vertically. It retained those boundaries for ten years before the increasing population called for changes.
In 1785, the township of Frankstown was divided roughly in half by a north-south line that followed the summits of Lock Mountain and the east branch of Brush Mountain. The eastern part that was removed from Frankstown received the name: Woodberry Township. The new township could have, and perhaps should have been given the name: Morrisons Cove Township because the region it encompassed was primarily that cove.
In 1787, the county of Huntingdon was erected out of Bedford County by the plotting of a roughly southeast to northwest diagonal line. The eastern starting point of that dividing line began on the summit of the Tuscarora Mountain just a short distance to the east of Burnt Cabins and Fort Littleton. The line was plotted in the northwest direction through the gap defined by Dunnings Mountain and Short Mountain, once known as Frankstown Gap, but later McKee Gap. It then extended on westward through Blair Gap in the Allegheny Mountain. The erection of Huntingdon County divided Woodberry Township in two. That portion of Woodberry Township which lay north of the present-day towns of Martinsburg and Roaring Spring, Blair County would retain the name of Woodberry and would, in 1787, become part of Huntingdon County. The southern half also retained the name of Woodberry Township within Bedford County.
Thirteen years later, in 1798, Woodberry Township in Bedford County was divided by a north-south line which ran along the ridge of Dunnings Mountain. The portion which lay to the east retained the name of Woodberry. The western half of Woodberry Township was named Greenfield Township. Forty years would pass before any further changes were called for.
In 1838, the township of Woodberry in Bedford County was divided into South Woodbury and North Woodbury. Although the exact date is unknown, the change in spelling of the name Woodberry to Woodbury probably came about at that time. In 1844, the region that is encompassed by the present-day Woodbury and Bloomfield Townships was organized as Middle Woodberry Township within Bedford County. For a period of two years there existed, within Bedford County: North, Middle and South Woodbury Townships.
Then in 1846, Blair County was erected out of the western half of Huntingdon County. At that time, a portion of the northern third of Bedford County was removed and attached to Blair. Greenfield Township in the west along with North Woodbury in the east now came under the jurisdiction of Blair County. That left South Woodbury and Middle Woodbury in Bedford County.
The last division of what was, in 1785 defined as Woodberry Township came nearly a century later. In 1876 the township of Middle Woodbury, situated north of South Woodbury, was divided approximately in half by a surveyed north-south line running through the valley between Dunnings Mountain in the west and Tussey Mountain in the east. The word 'middle' was dropped from the name of Middle Woodbury for the eastern half, and the western half was given the new name of Bloomfield.
The new township's name was probably derived from the Bloomfield Furnace, which was in operation from 1845 through the 1870s. The furnace, itself had been named by its owner, Dr. Peter Shoenberger, who usually named his furnaces and forges for his various daughters. The exact origin of the name Bloomfield is anyone's guess. One possibility might be the place where iron blooms were either produced or stored. A simple (i.e. crude) type of furnace in which iron was smelted from iron oxide was called a bloomery. The resulting product of a bloomery was a somewhat porous mass of iron, called a bloom. Sometimes referred to as sponge iron, the bloom of iron contained a percentage of unseparated slag. Bloom iron tended to need additional heating and hammering in a forge to produce what was known as wrought iron. The word 'bloom' was derived from the Middle English blome meaning a lump of metal. That was derived from the Old English bloma meaning, variously, a lump of metal, or mass.