Here's why only 4 US states are called 'Commonwealths,' and the significance behind the label

The question of commonwealths becomes a bit more complicated when we move beyond the continental United States to look at a few of its island territories.

The US has five major territories: American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands. Of these five, only two of them are considered commonwealths — the Northern Mariana Island and Puerto Rico.

Like their state counterparts, the use of the term commonwealth in the full titles of these territories does not affect their legal status.

Though it legally has no significance, the title of "commonwealth" has come into question during disputes over the future of Puerto Rico's status as a territory — namely, in the debate over whether the territory should remain as it is, become independent, or become a fully integrated US State.

Some supporters of Puerto Rico's independence have supported a kind of fusion status that would utilize the term commonwealth and grant the territory rights similar to those of a Free Associated State, including the right to manage their own international affairs while still maintaining a special relationship with the United States.

The term commonwealth is also still used beyond the US, notably in the Commonwealth of Nations – a 53 country intergovernmental group which includes countries such as Canada, Australia, South Africa, and India — where nearly all the countries share a history of being ruled by the British Empire as a territory or colony.

While most of these commonwealth countries are independent from the United Kingdom today, Queen Elizabeth II still serves as head of state for 16 countries in the Commonwealth of Nations, including Canada, Jamaica, and New Zealand.

Despite these countries having no legal obligation to one another, they do share a set of common goals. In its charter, the group commits to "the development of free and democratic societies and the promotion of peace and prosperity to improve the lives of all peoples of the Commonwealth." Again, the term commonwealth here is used to emphasize the vision of a democratic and prosperous political community.

These countries also share a common appreciation for friendly competition and participate every four years in a sporting event — much like the Olympics — called the Commonwealth Games. Hosted most recently in Australia in 2018, athletes from these commonwealth countries come together to compete in sports like swimming and diving, table tennis, and gymnastics.

While the term commonwealth can be almost entirely dismissed as a remnant of political language from centuries ago, it is also a lasting reminder of the goals and ideals of politicians who shaped these nations — and a reminder of what those nations are still striving to achieve every day.