Although it was a growth industry, the billboard advertising business was a tough one.
Then they were nothing more than town and city wall spaces used to advertise businesses or, just as often, upcoming public events.
Eventually that method gave way to printing the billboard displays on sheets and assembling them at the "plant" (the site of the billboard).
Today, most billboard advertisements are prefabricated as computer-designed and precision cut vinyl pieces and can be assembled with an efficiency far beyond what the technology of Charles Lamar's day allowed.
Obstacles to the growth of billboard advertising companies arose in the form of state and local zoning regulations that did everything from imposing permit requirements to specifying the allowed locations and size and shape of the displays.
Nevertheless, the industry steadily prospered, especially after World War II, when the average American family could again afford to buy an automobile.