Dr. Dawinder S. Sidhu, professor of constitutional law and national security at the New Mexico School of Law, wrote an article[1] in which he presented the historical actions of Eldridge Gerry Spaulding, chairman of the House Ways and Means Subcommittee on Banking and Currency, to create the fiat currency known as the greenback.
The advent of the greenback, green paper currency not backed by anything of intrinsic value, like gold or silver, created as a war measure in 1862, was a lawless act because it violated restrictions in the Constitution prohibiting such measures.