The state that has the most miles of coastline is Alaska. It has 6,640 miles of coastline compared to California's 840 miles.
Maine.....
it is Maine due to it's many coves
Alaska
Alaska besides being the largest state, is surrounded by the Pacific ocean, the Bearing sea and the Arctic. It has many islands and they all count for shoreline.
California.
According to infoplease, Florida has 580 miles of Atlantic shoreline, plus 770 miles of Gulf shoreline, making a total of 1350 miles of ocean front. California, on the other hand, has 840 miles of Pacific shoreline. Therefore, if you count the Gulf of Mexico, Florida has more ocean front. If you ignore it, California has more ocean front. Please see the related link for details.
Mississippi
The state of Minnesota has more than 90,000 miles of shoreline. This is more than the states of Florida and California.
Alaska is the state with the most shoreline because it includes many islands and the state itself is enormous. Behind that would probably fall California and Florida.
Hawaii, and on the mainland, Florida.
Minnesota
No state has both. Alaska has the longest State Border with Canada. Florida has the longest Atlantic shoreline.