Part of the Treaty of Ghent's job was to clarify ambiguities in a prior treaty—that's right, these treaties were as confusing at the time as they are now.

The Treaty of Ghent makes a few references to the Treaty of Paris from 1783, which ended the Revolutionary War and established the original boundaries between the United States and Canada. In 1814, both sides saw a need to reconsider disputed territory within the context of the old treaty—hence the need for arbitration commissions established in Article Four.

Unlike Ghent, the Treaty of Paris had settled things in a way that decidedly favored the United States. Obvs—the British officially recognized that America was its own thing. The King lost thirteen colonies and got nothing back, although he got to keep Canada.

After the War of 1812, on the other hand, nobody got to keep anything. No wonder we don't celebrate December 24th as the day the Treaty of Ghent was ratified. That date on the calendar is a little cluttered, anyway.