What is the distance north to south in

* Northernmost point: Point Barrow, Alaska (71°23'20'' N)

* Southernmost point: Ka Lae, Hawaii (18°54'08'' N)

Distance: 4,900 miles (7,900 km)

Canada

* Northernmost point: Cape Columbia, Nunavut (83°06'41'' N)

* Southernmost point: Point Pelee, Ontario (41°43'18'' N)

Distance: 2,900 miles (4,700 km)

Mexico

* Northernmost point: Tijuana, Baja California (32°32'08'' N)

* Southernmost point: Tapachula, Chiapas (14°53'26'' N)

Distance: 1,900 miles (3,100 km)