Once, Obamacare’s defenders were certain the Supreme Court would uphold the individual mandate requiring every citizen to purchase health insurance. Then came the oral argument. Solicitor General Donald Verrilli was unable to articulate a limiting principle to Congress’s powers. That set off a scramble to find historical precedent for the individual mandate.

Enter Law professor Einer Elhauge. He’s “discovered” three Founding-era purchase mandates supposedly similar to the Obamacare mandate: the 1790 act to regulate commercial ships, the 1792 militia act, and the 1798 act creating a fund for sick seamen. However, none of these laws sets a precedent for the federal government to require every individual to purchase health insurance.

The 1790 act regulated all ships engaged in foreign commerce and large ships engaged in domestic commerce. Most of the regulations addressed contract disputes, desertion, and what recourse the crew had if the vessel was unsafe. It detailed penalties for sailors and captains who failed to comply with the regulations.

Congress also required ships to have the modern-day equivalent of a first-aid kit: a “chest of medicines, put up by some apothecary of known reputation, and accompanied by directions for administering the same.” If the captain failed to provide that kit, then he would be required to pay his sailors’ medical costs “during the voyage.” This is not insurance or even really a purchase mandate; it’s a penalty for ship captains who failed to comply with a safety regulation.

The 1792 militia act required each member of the militia to “provide himself” with “a good rifle, knapsack, shot-pouch, and powder-horn, twenty balls suited to the bore of his rifle, and a quarter of a pound of powder.” Congress passed this law in accordance with its Article I, Section 8, Clause 16 power “To provide for organizing, arming, and disciplining the Militia,” a clause that gives Congress broader power over members of the militia than over average citizens. Not every American was required to have these goods, only members of the military. This law was a national security necessity in the 1790s whenAmerica lacked a standing army. As theUnited States transitioned to a professional military, it dispensed with the militia requirements.

Essentially, Elhauge argues that it’s irrelevant why Congress enacted these laws or which clause empowered it. To him it only matters that Congress did so. By this logic, Congress should be able to pass any law it wants as long as it has done something similar in the past.

Similar to the 1792 law, the 1798 law was a national security measure passed because the country lacked a standing army and navy. Here’s how the law worked: When American ships arrived at aUnited States port from a foreign port, the ship’s master would pay a fee of 20 cents per sailor, which he could deduct from the sailor’s wages. The President was authorized to spend the money “to provide for the temporary relief and maintenance of sick or disabled seamen” in port hospitals. Remaining funds (along with private donations) were put toward building maritime hospitals in ports of theUnited States.

To those grasping for precedent, this appears to be an 18th century Obamacare. But there are two key differences. First, as legal historian Philip Hamburger notes, early Americans would have recognized this law as a version ofEngland’s “Chatham Chest”—a government fund consisting of money deducted from sailor’s wages used to support disabled sailors.

Unlike Britain, Americain the 1790s lacked a strong navy. Merchant ships were the navy. Congress used the Marque and Reprisal Clause to give private merchant ships the power to attack and seize enemy vessels during war. In June 1798, as a result of the Quasi-War withFrance, Congress abrogated existing treaties withFrance and authorized merchant ships to attack French vessels. This change meant that “all merchant seamen were potentially engaged in the military struggle,” Hamburger notes. A month later, Congress enacted the 1798 law to fund naval hospitals and care for seamen as a part of the war effort. With the creation of a professional military, the marine hospital system was replaced by an official uniformed service—the U.S. Public Health Service Commissioned Corps.

Second, this fee is akin to a tariff, not a purchase mandate. The sailors weren’t buying anything. Instead, a fee was assessed from a specific group (sailors engaged in commerce with foreign ports). The government used those funds to provide a limited range of medical care at specific hospitals for those sailors. Unlike Obamacare, which requires every American to own a certain product, the sailors never owned anything.

Unlike Obamacare, these three founding-era laws applied only to individuals who were participating in an activity covered by Congress’s enumerated powers. These laws were not social programs.

Constitutional authority matters, and the context for these founding-era laws is significant. Precedent is found not by looking backwards at history to find justification for current policies, but by considering actions in the past in their own context and within the principled framework of the action. Obamacare is unprecedented, and soon we’ll see if the Supreme Court agrees.