I read an article posted on the front page earlier today about the new show Frontier. It's set in late 18th century Hudson Bay, Ontario (apparently, the James Bay area, to be more specific). Now, I know historical drama series aren't the best at historical accuracy when it comes to props/material culture, but the shoelaces on the boots caught my eye because I've only ever seen 18th-century boots sporting buckled bootstraps or just strapless boots (like the high-ranking British soldier on the right with the absurd amount of stiletto daggers he carries on his persona).
Is your question about boot fashion in the 1700s or about shoelaces as a feature of footwear more generally? Shoelaces can be found in some form on footwear going back thousands of years.