British and American English differ in several consistent spelling patterns — for example, British "-our" endings become American "-or" (colour/color), and several other systematic swaps follow similar patterns.
Most of these differences trace back to Noah Webster's early 19th-century American dictionaries, which deliberately simplified many British spellings.
Neither spelling system is "more correct" — the right choice depends on your audience, and the most important thing is staying consistent throughout a single piece of writing rather than mixing the two.
Last reviewed: September 2026