Many states explicitly require by law consummation of marriage for the vows to be considered valid. They include Alaska, Colorado, Connecticut, Delaware, Idaho, Illinois, Michigan, Minnesota, Montana, Ohio, South Carolina, Vermont and Wisconsin.
http://wiki.answers.com/Q/Which_states_require_consummation_for_marriage_to_be_a_legal
http://wiki.answers.com/Q/Which_states_require_consummation_for_marriage_to_be_a_legal
Don't believe everything you read on the internet. Especially when references are not given.
Minnesota, for example, does NOT explicitly require consummation. I imagine quite few other states are like them. What they do allow is the annulment of a marriage which is not consummated and where there was fraud on the part of the partner at the time of the marriage who hid the fact that they were incapable of consummating the marriage.
Ironically, your list of 13 supposed states requiring consummation include 4 states which allow same sex marriage: Connecticut, Delaware, Minnesota, and Vermont.
How could the state possibly enforce such a requirement? What proof would be required to satisfy the requirement?