Boston, new york philadelphia, charleston. what do the location of all four cities have in common

Here is the correct answer of the given question above about Boston, New York and Philadelphia. The three cities given above were part of the 13 British Colonies. Also, these cities are significant before, during and after the American Revolution. In addition, these cities are large cities even before until the present and each has their own airports. Also, these cities are seaports, and multi ethnic. Hope this answer helps.