History of the USA's GROSS DOMESTIC PRODUCT?

There are a few main indicators for how our economy is doing... in general the "GDP" is considered the "best economic indicator" as well as Consumer Price Index (CPI) and Housing and Labor Data. What else is helpful? I've found that "price oscillator" are very helpful for studying "data that always seems to be going up.. for example GDP or population data? A price oscillator is the "difference" between two moving averages typically one "long and one short" and acts similarly to a "variable waveform derivative" in calculus. Price oscillators are also very helpful for studying heath data for example heart rate data or blood pressure.

INTERESTING OBSERVATIONS FROM THE PRICE OSCILLATOR OF THE us GDP?
1. It shows that something changed for the better around July of 2009? This maybe from the housing market crash of 2008 and a recovery around July of 2009?
2. However what cased the "GDP slowdown" problem in the USA around January of 1979?