These were one of my earliest building toys

Lincoln Logs were released to the general public around 1916.  

They were created by John Lloyd Wright (son of Frank Lloyd Wright)

https://en.wikipedia.org/wiki/Lincoln_Logs

Playskool purchased the J.L. Wright Manufacturing Company in 1943.   By this time, Lincoln Logs were known as "America's National Toy"

Playskool was the company that I recall producing them when I was young and playing with them. 

I used them in a huge portion of my childhood play, from just building new structures to building forts for my armymen to terrain, albeit oversized, for the roadways that my Matchbox cars would drive on.

I spent many childhood hours building with these virtually indestructable wooden toys.