July 1936 was pretty unreal for a very broad region though. Including well away from the agricultural belt of the Plains. It seems that it was very much a June 2021 style heat dome.
Central Park's all time record high of 106 still stands from that event.
Possibly, yes. Though then you have states like NY and ME where agriculture is not a factor, with all time record highs set in the 1910s/20s.
Truth is, the +CGT pattern was simply expressed more prominently during the first half of the 20th century, and it may have nothing to do with human activity at all.