For many years, I was a member of a Search and Rescue team. We were called out on a mission to find a climber in a neighboring county. The only map they sent us was a fax of the map on the cafe’s place mat. Not exactly up to topo standards.
Then, they instructed us to go down a certain county road until we came to where the old post office used to be. Okay… Very helpful.
Now, being that most of the SAR members were guys, we drove around a long, long time before stopping to ask for directions. Of course, the people at the house where we stopped knew exactly where the old post office used to be. Eureka!
Small towns are like that. Often you’ll hear county roads not referred to by the number on the sign but by the landmarks found on the road. To locals, that’s dandy. To newcomers, not so much. You’ll also hear directions like “go down to the house where Sam Smith lives…”. Again, not helpful if you don’t know Sam Smith.
On another occasion, when we were looking to buy land, we were given directions that said to drive until you see “a rock and a tree.” 
Like there is only one rock and one tree in that area of Colorado? Helpful.
So what does this have to do with 1775?
Well, today I’m reading a book that was written in 1868 about the town of Lexington. The section I’m reading tells of the founding families of Lexington – some of whom were represented in the events of April 19th 1775. He’s talking about the Winship family in 1650, telling us that “Lieut. Winship as he was generally called, erected a saw mill on what was then denominated Bill Brook, on or near the site of the present fur factory.”
Since the maps we have of Lexington are almost as good as a cafe place mat, I struggle to place the homes of the people I’m writing about. This little bit in this old book is not helping.