The fundemental question behind the development of Austrian monetary theory is not why there are booms and bust, but why these errors of judgement occur throughout the economy in often times very different sectors at the same time. Turns out this is more often than not because of significant, and crucicially, artificial distortions to the price system that causes resources to be put to use in places where they otherwise would not be, and creates illusions of profits to those who control said resources (individual employees, investors, executivies in companies etc.). Eventually the law of scarcity catches up, and the bust materialises and prices realign themselves (through deflation, which establishment economists are terrified of) to what they should be in a natural price system.
The only way to avoid this inevitable deflationary collapse of prices is to continue the illusion, of course, which is what central banks have been doing since 2008. This makes the eventual realignment much worse though since the price system continues to be distorted to an extent larger than it previously was.
The panics that occured prior to the instatement of the Federal Reserve were more often than not caused by either inflationary policies pursued by the the Treasury and general government interference, as was the case in the panic of 1907 in an effort to save overleveraged banks, or overextension of credit (and consequent overexpansion of the money supply) by fractional-reserve banks. In most cases however, these recessions resolved themselves rather quickly and did not lead to prolonged depressions and recovery periods like we saw in the 1930s during the Great Depression.