Johnstown is a compact rural community in the United Counties of Leeds and Grenville, in eastern Ontario, Canada, part of the township municipality of Edwardsburgh/Cardinal. It is at the Canadian terminus of the Ogdensburg–Prescott International Bridge and at the southern termini of Highway 416 and Highway 16.

History Prior to the arrival of Europeans, Johnstown and the surrounding area had been sporadically occupied by various Indigenous cultures for many centuries. Evidence of their presence such as clay utensils and arrowheads have been found throughout the township.Edwardsburgh Historians (1995) Edwardsburgh Township History. Henderson Printing Inc. No physical evidence of significant Native American settlements, such as longhouses, have been discovered within the hamlet itself, however the hamlet was apparently frequented by Natives. According to the Edwardsburgh Centennial Committee, who compiled a history of the township in 1967, Johnstown was used by Native Americans as a stopover place due to its location.A History of Edwardsburg. (1967). Spencerville, Ont.: The Committee. Before the construction of dams and later the Saint Lawrence Seaway, Johnstown was fronted by calm section of the St. Lawrence River located between two rapids. This would have made the land of present-day Johnstown a convenient place for those travelling on the river to rest. When the French arrived in the 1600s they were met by the Native Americans at Johnstown, who were essentially responsible for inspiring the French to settle here.

French period (1673–1760) The first regular land occupancy began in 1673 when French settlers, along with the allied Natives, built a fortified storehouse in present-day Johnstown, then called La Veille Gallette. The storehouse was situated on the shores of Old Breeches River, now called Johnstown Creek, and was used to hold supplies headed upriver to fur trading posts such as Fort Frontenac (Now, Kingston). It was in use until 1758.

In 1760, the French constructed a fort near Johnstown called Fort de Lévis. The fort was located on Chimney Island (Formerly known as Isle Royale) in the St. Lawrence River just off of the shores of Grenville Park. It was built in preparation for a British attack as an attempt to block their advance down river. The original design, created by and named after Francis de Gaston, Chevalier de Levis, intended for the fort to be built with stone walls, have 200 guns, and house 2,500 troops. Instead, the fort was built much smaller and of wood, with five cannon and about 300 soldiers. In the same year it was built, the fort was captured by the British during the Battle of the Thousand Islands. After a week-long standoff, the 11,000 British troops led by Jeffery Amherst succeeded in taking the fort from the few hundred French. The French troops managed to significantly delay the British arrival to Montreal, and succeeded in sinking two ships as well as crippling a third. The number of British casualties was 26 dead and 47 wounded, while the French saw 275 of their 300 troops killed or wounded. The British renamed the captured fort Fort William Augustus.

Settlement: 1760–1808 During and after the American Revolutionary War, those in opposition to American independence were dubbed Loyalists, and ultimately became refugees when their opposition was met with violence. Thousands were displaced who then fled to Canada, relying on the British Crown for a solution. As part of a resolution, townships were surveyed in the 1780s along the St. Lawrence River in present-day Leeds and Grenville, which included the township of Edwardsburgh/Cardinal. By 1784, 166 Loyalists were residing in the township and until 1790 the landing point and base camp for these settlers was at Johnstown. Loyalists intended to turn the base camp into a new townsite.

In 1788, plans for a town site were drawn up with a plot of . The plan was created by the government Land Committee with strict regulations in regards to the layout of houses and streets. By 1789, a number of Loyalist men were placed in charge of selecting the location of the town site, at that time called simply "New Town". The agreed upon site was that of present-day Johnstown. The name Johnstown was selected in 1790 after a pastor suggested they name the town after Sir William Johnson.

In 1792 John Graves Simcoe, the first Lieutenant Governor of Upper Canada, established himself in Johnstown which then became the district’s administrative seat or "capital". This led to the court of quarter sessions (the district's government) alternating its meeting location between Johnstown and Cornwall, and to the construction of a courthouse and gaol. The courthouse was a log structure, which stood near the present site of the Ogdensburg-Prescott International Bridge. By the late 1790s, the village was also home to a sawmill, gristmill, and an inn and tavern. Census records indicate by 1807, there were 36 houses and a general store.

In 1808, the seat of justice was moved to Elizabethtown (now Brockville), as it was a more central location in the district. The move and village's shallow harbour prevented the village from ever reaching its expected potential.

1800s By the mid-1800s, Johnstown was less prosperous than many other Edwardsburgh/Cardinal communities. Most residents made a living through farming, while later into the century some pioneer industries operated in the village. The village relied on nearby Prescott for most services including the post office. The saw and grist mill which had been in operation since the late 1700s was sold during the 1800s and became known as Wharton's Mill for most of its operation. This mill was a gristmill, sawmill and carding mill. In addition to the mills, a pottery business called Mooney's Pottery provided employment opportunities for the village. Mooney’s employed around four men and made earthenware items such as ink wells or pots which were sold throughout the county.

By the last half of the 19th century, some pioneer tradespeople and businesses were active in the community aside from the mill and pottery manufacturer. This included a blacksmithing shop, a tavern called Finnegan's Tavern, the McAuley Motel, several hot houses, as well as a tourist camp called St. Lawrence Resort Camp. By the 1870s, the village had two grocery stores. Some business directories from the late-1800s indicate Johnstown also employed a village constable.

Early 1900s Johnstown began to grow as a village again by the 1920s when the grain elevator (now the Port of Johnstown) was constructed and highway traffic along Highway 2 increased. During this time, the village became home to three car garages, boarding houses and a barber shop. The construction of the St. Lawrence Seaway in the late 1950s and the international bridge in 1960 also contributed to an influx of people residing in Johnstown. During the 1960s many new homes and subdivisions were constructed in the village to accommodate the influx. Two new motels were constructed around this time, the Johnstown Motel and the Glen Motel, both of which have since closed.

From the 1960s onward Johnstown has continued to develop, becoming the township's industrial centre. In the late 1900s, the community was home to a variety of businesses such as a cable manufacturer, a machine and welding shop, an automotive repair shop, a Chrysler dealership, and a few others. Many of these twentieth century businesses have since changed or closed.

Modern day As of 2016, Johnstown remains the township's industrial centre. According to the township's website, the industrial park focuses on transportation and logistics, intermodal facilities and light manufacturing. In addition to the Port of Johnstown, the village is home to the companies Greenfield Ethanol Inc., Ingredion Inc. and Prysmian Cables.

In 2006, it was announced that Canadian ethanol producer GreenField Ethanol had plans to build a new high capacity ethanol production plant in Johnstown's industrial park. Construction commenced in 2007, and operations at the plant began in December 2008. By early 2009, the plant had reached full production levels. The plant can produce of ethanol per year, making it the largest ethanol plant operated by GreenField.

In addition to the industrial park and large businesses, Johnstown is home to a church, a Jehovah's Witness Kingdom Hall, an elementary school and a convenience store and gas station. A Duty Free store operates at the foot of the bridge for those travelling internationally.

Johnstown is also home to a recreation area. The recreation area consists of a community pool as well as two regulation-sized softball diamonds, three beach volleyball courts, two tennis courts, three horseshoe pits and a soccer field. Additionally, there is a community hall on site which is used year-round for community events including weddings, banquets or picnics.

Education and schools During the era of one-room schoolhouses, Johnstown went through three schools. The first school to serve Johnstown was a frame building called Lee School built north of Second Street. According to records, the Board of Education stated in 1834 that this school was the only approved common school within the township. This building was eventually replaced around the 1860s by a stone building near the Johnstown Cemetery. In 1902, this school was replaced again by a brick building, built at the corner of Queen Street and Ontario Highway 2. Upon its construction, the third, brick school was painted many colours; the wainscotting was red while the walls and ceiling were blue and the floor was yellow. In 1941, it was repainted in a more neutral palette. In later years, the school became known as Johnstown Public School. The final schoolhouse was closed and demolished in 1961, and the bricks were used to construct a bungalow on the same site.

In the 1960s, a newer, modern school was constructed in Johnstown called South Edwardsburgh Public School. Officially opened on September 14, 1961, the six-room brick school was built to replace numerous rural schoolhouses in the area. By 1967, two more classrooms were added as well as a kindergarten and a general purpose room. As of 2018, this school remains open. For post-secondary schools, students have the option of attending South Grenville District High School in nearby Prescott.

Churches Prior to any churches being constructed in Johnstown the home of a local man named John McIlmoyl and the old gaol house were used to house meetings for the Anglican and Methodist congregations, who were serviced by a travelling minister. Johnstown eventually became home to two churches, built over 100 years apart; a Methodist church and a Jehovah’s Witness Kingdom Hall.

The Methodist church was constructed in 1879 through volunteer efforts and donated money and supplies. The church is a small, red brick church located along the St. Lawrence River near the international bridge. The church was built with a drive shed that also served as the church hall. In 1925, the church became the Johnstown United Church after a church union. In 1962, the church was moved closer to the river when Highway 2 was widened. At this time, the church also received new brickwork and a basement to serve as the new church hall. The drive shed was given to a local farmer to house cattle. The church saw more renovations in the 1980s when an extension was added, the roof was replaced and a wheelchair ramp was built.

In 1990, a Kingdom Hall was built for the local Jehovah’s Witnesses in Johnstown after the congregation outgrew their church in Prescott. The building was built to accommodate 180 people, and was in a more central location to most of its congregation. The building was constructed mostly through volunteer efforts, and was completed in only three days.

Cemeteries