Financial sector growth before the Global Crisis

The graph below shows the the share of the Finance and Insurance industry in the GDP of the United States, estimated from 1850 to 2007 (source here; h/t to Eric Mielants for bringing the paper to my attention).

Note that basically there are three periods of increase in the financial sector's participation in GDP, the late 19th century, the 1920s, and if one discounts the partial recovery from the collapse during the Great Depression and WW-II period, the 1980s onwards. Deregulation has obviously something to do with this increase.