I guess you are one of those, that believes the governments create jobs and economic growth.
 
"From 1951 (the end of the Marshall Plan) to 1981 (the beginning of the Reagan tax changes), both GDP and private sector jobs grew at an accelerating rate."

During that time frame we were the major producers if manufactured goods. If you recall during World War most of the world's manufacturing had been bomb to near extinction. By the 80's the others countries had recovered and if you back in time you will find those were the days of "Made in Japan" and Germany and Japanese cars rush.

Tax laws and rates had nothing to do with it. Just like during the hay days of the Dotcom boom in the Clinton administration tax rates can be increase and maintained during good time but higher tax rates didn't create the boom