First, the enum methods shouldn't be in all caps. They are methods just like other methods, with the same naming convention.
Second, what you are doing is not the best possible way to set up your enum. Instead of using an array of values for the values, you should use separate variables for each value. You can then implement the constructor like you would any other class.
Here's how you should do it with all the suggestions above:
public enum States {
...
MASSACHUSETTS("Massachusetts", "MA", true),
MICHIGAN ("Michigan", "MI", false),
...; // all 50 of those
private final String full;
private final String abbr;
private final boolean originalColony;
private States(String full, String abbr, boolean originalColony) {
this.full = full;
this.abbr = abbr;
this.originalColony = originalColony;
}
public String getFullName() {
return full;
}
public String getAbbreviatedName() {
return abbr;
}
public boolean isOriginalColony(){
return originalColony;
}
}