The entire main page is filled with charts and graphs. All of them show some kind of significant shift beginning in 1971. There are over 75 of them!

Here is some more data from graphs on the website:

African-American incomes virtually stopped catching up to white incomes in 1971.

Median male income has flatlined compared to real GDP per capita since 1971.

The number of 2-income families has surged since 1971.

Price inflation has surged since 1971.

A can of Campbell's tomato soup has undergone significant shrinkflation since 1971. 

Housing prices have skyrocketed since 1971.

What in the World Happened in 1971?

Clearly, something significant happened in 1971 causing a tremendous economic shift. 

What was it?

President Richard Nixon severed the dollar's last connection with the gold standard, making it a purely free-floating fiat currency.

Nixon ordered Treasury Secretary John Connally to uncouple gold from its fixed $35 price and suspended the ability of foreign banks to directly exchange dollars for gold. During a national television address, Nixon promised the action would be temporary to "defend the dollar against the speculators."

Nixon's order was the end of a path off the gold standard that started during President Franklin D. Roosevelt's administration. June 5, 1933, marked the beginning of a slow death of the dollar when Congress enacted a joint resolution erasing the right of private creditors in the United States to demand payment in gold. The move was the culmination of other actions taken by Roosevelt that year, including his infamous "gold confiscation" order.