Thomas Clarke was born in Dumfries, Scotland in 1770. He immigrated to Canada in 1792 and initially settled in Queenston, where he was an apprentice in the store of his relative, Robert Hamilton for four years. In 1796, Clarke opened his own store in Queenston and changed the spelling of his last name to "Clark". In 1805, he built an estate which he named Clark Hill, on land overlooking Dufferin Islands. On March 30, 1809, Clark married Mary Margaret Kerr, a granddaughter of Sir William Johnson and Molly Brant. On July 9 of the same year, he was appointed a commanding officer of the 2nd Regiment of Lincoln Militia, in which he achieved the rank of Lieutenant-Colonel, and served with distinction during the War of 1812. In 1817, he was made a life member of the Legislative Council of the Province.
Samuel Street Jr. was born in Farmington, Connecticut on March 14, 1775. He was the grandson of Nicholas Street, a Puritan minister who had immigrated to the United States from England. Nicholas Street's two sons, Nehemiah and Samuel, who were both Loyalists, set out for Canada when the American Revolution began, but Nehemiah was murdered in Buffalo. Samuel Street came to Canada and was granted land in Willoughby Township sometime in the 1780's. Nehemiah's son, Samuel Street Jr. joined his uncle in Canada in 1796, and was granted land in Queenston. Soon after, he acquired control of Burch's Flour Mills, which came to be known as Street's Mills. Samuel Street Jr. was married to Abigail Hyde Ransom on September 5, 1811. While living in Queenston, Street Jr. became acquainted with Thomas Clark and they established a business partnership, Clark and Street, in the latter part of 1796. Samuel Street Jr. left the company in 1799, but re-established the partnership eleven years later, at which point Clark and Street undertook a variety of ventures –transportation, manufacturing, mercantile, banking and landholding –which greatly increased their wealth and prominence.
Clark and Street acquired the Bridgewater Flour Mills which, along with Street's Mills, were burned in 1814 by retreating American forces during the War of 1812. On April 15, 1825, they were granted a 21 year lease to operate a row-boat ferry across the Lower Niagara River. As a condition of the contract, they built a cobblestone carriage road (part of which is still in use today) down the side of the gorge to the ferry landing in 1827. In 1832, Clark and Street purchased the Pavilion Hotel from William Forsyth. Also in 1832, a consortium of prominent Upper Canada businessmen, including Clark and Street, purchased approximately 400 acres of land from Forsyth, to develop into a residential community known as the "City of the Falls" Project. Although this project ultimately failed to realize the expected profits, Clark and Street obtained large tracts of choice land in the Falls View area, and Clark Street commemorates the role that they played in this undertaking. In 1835, Clark and Street were among a group of businessmen who formed the Erie and Ontario Railroad Company. This Company proposed to construct a railway line to offset the loss of business caused by the opening of the Welland Canal in 1829. They were granted a charter on April 16, 1835, and built the Erie and Ontario Railway Line, which was also known as the Chippawa-Queenston Railway Line.
Thomas Clark died in October, 1837, bringing to an end one of the most powerful business partnerships in all of Upper Canada. As Thomas Clark had no children, his property and holdings were inherited by Samuel Street's son, Thomas Clark Street, who also became a prominent area businessman. Samuel Street died on August 21, 1844.