USPTO
The United States Patent and Trademark Office – the agency whose software patents supplied the patent trolls with their raw material.
The first US patent was issued in 1790; the office now sits in Alexandria, Virginia, under the Department of Commerce. In the 1990s the floodgates opened for software as the courts accepted algorithms and, with State Street in 1998, business methods. Examiners with a few hours per application granted patents on things that already existed, because software prior art rarely sits in a patent database.
The correction came in instalments. The America Invents Act of 2011 created the PTAB and inter partes review, letting anyone challenge an issued patent without a full lawsuit. Bilski in 2010 and Alice in 2014 tightened what can be patented at all. The trolls are still around; their costs have just gone up.