Bob, a lot of New England races were just arbitrary distances, sometimes point to point like Falmouth (between 2 bars; for years it was listed as 7.1 miles until I measured it and found it to be an exact 7).
The Westport Roadrunners Summer Series, the second oldest races in CT, which will be holding their 51st running this year, were designed as even distances (3, 4, 5 miles etc.) but were measured with the local police chief's car. By the time they were measured by calibrated bike and found to be off (most short, but a few actually LONG) there was too much history to toss out the courses.
Interestingly their distance has changed subsequently, as the measurement procedures changed from Shortest PROBABLE Route to the current Shortest Possible Route (there are a few measurers old enough to remember that change).
I particularly like running these each summer (the few races I actually get to run in) because my times there can only be compared to previous efforts on those courses - can't compare to any other "standard" distance. Of course the flip side of that is that I am generally getting slower each year