From the time of the earliest European settlements, what is now known as the Town of Souris was known by many names. The Acadians who first settled the area had to deal with a series of mice plagues, when hordes of mice swarmed the area, eating the crops and eventually drowning in the sea. A French vessel passing by the bay in the early 1700's documented having to cut through waves of mouse carcases. The area became associated with these plagues, and on a 1744 French map is named Havre a la Souris. Later maps by the English call it Mouse Harbour, and later Colville Bay, after the British Commander of eastern North America.
Mice do not hibernate, they continue to live and breed in colonies under the snow in winter, chewing on bark of tree trunks and foraging for food wherever possible, increasing in numbers all the time. A winter of heavy snowfall protects them from owls, foxes and other predators. In the early years of the Island settlement there were, at least, four plagues of mice: 1724, 1728, 1738 and 1749. The destruction by the mice was not in the early spring but later when the grain was growing. The mice covered the fields in swarms, ate every blade of grass and went on to devour the marsh hay, so essential for the livestock.

So numerous and so determined were the mice that swarmed over the land, that they frequently raced through the settlers' homes. The late Mrs. George Mellick of Souris told the story of how her grandmother, as a small girl, was given a horsewhip and told to whip the mice away from her father, John longuephee, as he lay in bed in pain from a broken leg.

Over the years other names have come and gone, such as Grand Haven and Red Cliffs. It was not until the post offices came into existance that the name Souris was established.

Edward Abell was a land agent for Lord Townshend. He was hired to collect rent from tennants. He went o the home of Patrick Pearse, and refused to accept the rent because it wasn't entirely in British currency. Pearse was able to collect the proper funds from his neighbors, but as he was returning to his home he witnessed Abel in the process of confiscating his beautiful black horse in place of the rent. It was known that Abel's wife wanted the horse. In a rage, Pearse stabbed Abell with a bayonet. A large reward was offered for his capture, but sympathetic neighbors assisted Pearse in his escape.

A play about the incident, called "For the Love of a Horse" was written by local historin Adele Townshend.

To undestand the early settlement of Souris or any other Island community, the story has to be told of the infamous British plan for land development; of how responsibility for the newly acquired Island of St. John (as PEI was then called) was casually passed over to about 100 outstanding British political, and military figures who had served the Crown well. The new owners, most of whom had never been to the New World across the Atlantic nor had any idea of pioneer conditions, were now responsible for seeing that new inhabitants were sent out to settle the land.

The Line Road Riot took place in March 1843. Those in conflict were Lawrence MacGuire, whose job it was to prevent tresspassers on the land of Samuel Cunard, and Martin Haney, a tennant who had twice been evicted from his home on Cunard's property. MacGuire moved into Heaney's former home to prevent re-entry.

The neighbors were angry with the number of people who had been charged with tresspassing on the Cunard land. They held a meeting which turned into a mob which proceeded to McGuire's. He held them off with a musket. He was persuaded to return to his home in Souris under protection. A week later, while he was staying with the Justice of the Peace for protection, his own home in Souris was burned.

A Civil and Military force was soon after dispatched from Charlottetown to restore order in Souris. Thirty eight people were arrested and tried in Supreme Court for alledgedly burning MacGuire's house. None were convicted. Tempers flared after the troops had gone, when Scottish settlers in St. Margaret's accused their parish priest of lodging some of the troops. Reverand John MacDonald was obliged to take another parish. Such protests which occurred in the Souris area helped to hasten reform.

The demand for wooden ships began when England turned to the colonies for ships during the Napoleonic War. Lacking in their own supply of timber and cut off from other European sources, the English government turned to the abundant natural resources of its North American colonies.

Souris benefitted greatly during this shipbuilding boom. The industy grew and reached its peak in the 1860's. During this time there were 200 - 300 people employed in various shipyards on the Souris River. In 1863 one hundred ships were built in Souris and sold in England at inflated prices by the United States Civil War.