The article is partly innaccurate.
There was indeed a mandate to buy guns. This power is given to congress by the part of the constitution that gives congress the power to arm the militia:
"To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;"
There wasn't a mandate to buy health insurance for seamen. There was a tax on their pay, which was used to set up public hospitals for injured or disabled seamen. Also, ships were required to have medical chests. This was done under the power of the constitution to provide for a navy, as private seamen would be called to serve in the navy in the event of war:
"To provide and maintain a Navy;"
The article is BS and it has nothing to do with obamatax.