The Continental Congress passed matrimonial legislation? I have no doubt that they would have found gay “marriage” to be abhorrent, but you are stating the factual point that the Continental Congress passed laws regarding marriage. Prove it.
The Continental congress had to make law regarding what is a legitimate marriage, just as the government always does.
The first law regarding widow benefits at the federal level was in 1780. Naturally they had to have a definition of what they considered a legal marriage, and two men were not going to pass muster.