They were a local co (Alexandria Drafting Co.) which did its own original work in our region (at least, starting in our region).
Since they were bought by German language/map behemoth Langenscheidt, they changed. They’re still excellent, but sometimes more out of date than they used to be. I hear they’re owned by another co., now.
I learned about them when my mother was in Real Estate - huge thing. They were still local. We always had some of the most local maps on hand. I started relying on them heavily just for my local forays looking for graveyards, etc, just exploring the back roads.
After Langenscheidt I noticed some errors, sometimes just things that weren’t updated for new traffic patterns.
Regardless, I love the things and as a birthday present, my husband bought all ADC maps for Maryland, so we had them all on hand and all were consistent with each other, at least!
Thank you for the explanation! I much prefer the ADC maps to GPS, MapQuest or even to iPhone mapping; although the latter is really handy if you don't have an ADC book of the area. You get a more comprehensive slug of information at a glance, such as where the post offices are and all the surrounding street names, parks and points of interest.
Oh, and WOW! That's an awesome gift! Kudos, OILineHubby!