Each state gives the license and the requirments are different for each state. Some states are pretty strick and others aren't. You will probably have to take a test in any state for a license. Most require you take a motorcycle saftey class and/or pass a test in addition to a test for a standard license.
An international license with motorcycle endorsement might keep you from having to take the motorcycle class and test in some states.
Basic laws are the same in every state because they lose funding from the federal gov. if they don't adapt the basic laws. Others have additional laws, like lane splitting or manditory helmets.
Generally you will find the urban populated states are more strict than the rural less populated states.