I found a copy of a 1930's Mobil™ map of Missouri. Here is what the Kansas City area looked like way back when.
Note how the world ended about 75th Street (before freeways). Lee's Summit and Olathe were train stop blips.
Here is what the Northland look like.
I found it interesting the Barry Road was lettered as Route T from US 71 out towards Weatherby Lake. I didn't realize the section from US 71 over to Indiana was Route A nor the section from Indiana to Liberty was Route H. Route 1 was Route J.
US 65 from Springfield to Branson was quite "squiggly."
You can download the entire 43MB PDF here.