The first building in Craigleith was known as the Lunan House, built circa 1856. It was built to become an inn, and it was relatively popular for travellers along the Gravel Road (now called Highway 26). The first industry that came to Craigleith arrived in 1859, when William Darley Pollard knew there was a market for crude oil. And so, he began extracting bitumen from the shale, then distilling it for oil, to sell to nearby customers. Despite what seemed like a dream process, it was cut short in 1863. This was due to the inefficient process of harvesting the crude oil - oil which could've been much more easily harvested in nearby Sarnia. A very infamous episode in the history of Craigleith was the sinking of the Mary Ward. The Mary Ward was a ship that sailed in the 1870s, before it crashed 2 miles off the shore of Craigleith in 1872. Despite being a major catastrophe (spilling 300 barrels of oil and salt), only 8 lives were lost, due to tremendous rescue efforts from locals and George Collins, the local lighthouseman.
"Craigleith" is a rock in Scotland, literally meaning "Leith's rock (or craig)". Usually, North American names are just British names brought over from whatever town the immigrants were from, and I doubt this was any different for Craigleith.