patriot, expatriate

Patriot or patriot means someone who loves his or her country, or who supports or defends it--
He always wore a flag pin, and considered himself a patriot.
He was honored as a patriot who had served his country.

Expatriate or expatriate ( almost rhymes with patriot ) most commonly means a person who has left his or her country to live in another country, although it may be used as a verb, meaning to remove someone from his or her country, or to remove one's self--
He wrote his most famous novel while living as an American expatriate in Paris.
He lived as an expatriate for several years after the World War I.

Now that you know that, you can say--
"After living many years as as an expatriate, he returned to America and proved himself a patriot."

Note--an "expatriot" or "ex-patriot" would mean someone who once loved his or her country, but who no longer does, no matter where he or she lives--
He is so disgusted with the government that he now considers himself an ex-patriot.
Note  # 2--to "repatriate" means to return someone to his or her country--
We will try to repatriate all of the war refugees in the next several months.
Note # 3--not to be confused with "expatiate", meaning to expand or to enlarge upon a subject, in speech or in writing--
Once he begins to talk about politics, he tends to expatiate until he has exhausted the subject.