Accessibility

We aim to meet WCAG 2.2 at level AA, and to give every map state a text equivalent.

• The time slider is a standard range control: arrow keys, Page Up and Page Down, Home and End all work, and buttons step to the previous or next year with a cession.
• Everything on the map is also in the list beside it, and every cession has its own page.
• Map colors are from a colorblind-safe set, and line patterns show the kind of instrument, so color is never the only signal.
• The homepage’s historical map plays once and has pause and year controls. It stays still if you prefer reduced motion. On the full atlas, “Play years” is off by default and disabled if you prefer reduced motion.
• Names are shown in their own scripts and spellings, including Cherokee and Osage syllabaries, with fonts that cover them.

If something does not work for you, tell us.