We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Bad argument for several reasons. The U.S. was experiencing industrialization, when people moved from low productivity agricultural jobs to higher productivity industrial jobs. This is the same process that is occurring today in China. Once most workers are in industrial jobs, then growth rates moderate.
Also, it's difficult to estimate GNP previous to the twentieth century, but the figures cited are at the high range of estimates. By most estimates, similar rates of growth were experienced from 1960-1970 and from 1935-1945, periods with very high income tax rates.