The “Ironclad Test Oath,” which became law in 1862, differed in one crucial way from most pledges. Most oaths are promissory notes. A person pledges that in the future he or she will be loyal to a government or tell the truth. The Ironclad Oath included the promissory note, but it also featured a background check to include swearing, “I have given no aid, countenance, counsel, or encouragement to persons engaged in armed hostility … to the United States” or “pretended government.”
