From 1800-1930 the USA ran Budget Surpluses 2/3rds+ of Years. What Happended?

Before 1931, the federal budget always approximated balance except during three major wars, the American Revolution, the Civil War, & WWI…& we always paid down the debt after the wars. More than 2/3rds of years we had budget surpluses. John Maynard Keynes popularized Demand-pull economic theory & since the 1930s we have 23 trillion in natl debt. How long can we let the debt grow faster than the economy before we get in trouble? How do we change our ways & save the country for our children? ⬇⬇⬇⬇⬇ https://www.amazon.com/Economic-Clarity-Political-Confusion-Classical/dp/0578430215/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=1547765974&sr=1