This quiz groups two overlapping sets of states: California, Arizona, New Mexico, and Texas, which together share the roughly 1,954-mile US-Mexico border, plus Louisiana, Mississippi, Alabama, and Florida along the Gulf of Mexico coastline.

The four Mexican border states each have a distinct relationship with the boundary, from Texas's long stretch along the Rio Grande to California's short but heavily trafficked crossing at San Diego–Tijuana.

The Gulf Coast states share a different geography — flat coastal plains and heavy exposure to hurricanes — but each brings its own cultural imprint: Tex-Mex cuisine in Texas, Cajun and Creole traditions in Louisiana, and strong Cuban and broader Caribbean influence in southern Florida.

This quiz tests capitals across both groups, treating the southern edge of the country as one connected geographic and cultural zone rather than two unrelated regions.

The Rio Grande forms roughly 1,254 of the border's total 1,954 miles, making it by far the longest natural segment — the rest, mostly in California, Arizona, and New Mexico, runs through desert terrain marked by fencing and survey monuments rather than a river. Louisiana stands apart administratively too: it's the only state divided into parishes instead of counties, a holdover from its French and Spanish colonial history. Florida, meanwhile, is closer to Cuba than to Georgia at its southern tip — Key West sits just about 90 miles from Havana.

Mississippi and Alabama both sit fully within the Gulf Coast's hurricane-prone zone despite having comparatively short coastlines, sandwiched between the much longer Gulf shorelines of Louisiana and Florida on either side. New Mexico, despite sharing a Mexican border, has no Gulf or Pacific coastline at all, making it the only landlocked state in this entire grouping.