How the Union Grew

Thirteen British colonies became states in the Revolution. Admission since then has followed a political pattern more than a geometric one: territories, population, and Congress. Vermont (1791) was an independent republic first. Texas was a republic too. California skipped the usual territorial apprenticeship after the gold rush.

The Northwest Ordinance of 1787 set an early template: territories could become states on equal footing, not colonies of the original thirteen. That promise — equal states, not a core and a periphery — is why Wyoming’s two senators count as much as California’s.

The last two, Alaska and Hawaii, arrived in 1959. The flag’s fifty stars date from 1960. Five inhabited territories remain: Puerto Rico, Guam, the U.S. Virgin Islands, American Samoa, and the Northern Mariana Islands. They are part of the American story even when they are missing from the classroom map.