Brewing History - How Did Malt Procurement Adapt Over the Years?

I can imagine sourcing even the most basic ingredients must have been a significant challenge for a tiny brewery in the 60s. I remember once we had a brewer from Coors who came and she saw the black malt in the brew house. Those malt's were just not used in American brewing as caramel coloring was the tool of choice. We bought all of our malt, it was pale malt, from the local malt-scared Bowers-Wyitzer which was just across town.