The lower 48?

[boncey]

What is the reasoning behind the statement "the lower 48"?
I know it means all of the American states except Alaska and Hawaii, but why do they say "lower"?
Hawaii is not above the other states in the same way that Alaska is.
I don't get it.

[geofbob]

I hope an American can give you an authoratative answer. But I guess that the phrase was used before Hawaii became the 50th state in 1959, because as you say Alaska was "above" (ie north of) the other 48 states; and that the expression has continued to be used, though it is now not geographically accurate. Also, other phrases, such as the "first 48" or the "mainland 48" might not be considered politically correct, as they might imply the precedence of the earlier 48 states over the later two,

[homer]

The lower 48 states are 'contiguous' - that is they all have a border with another state.