You need a passport to cross the border?
You may be able to leave without a passport, but you may not be able to enter another country without one.
Since Zimmerman was born an American, there’s no guarantee that he could stay in Peru. I don’t know the laws, but Peru is Peru and not America.
Only if your leaving. If your'e entering you can easily swim or walk across.
You don't need a passport to leave the US.Having left the country a number of times,including as recently as two months ago,I've never had to show a passport to a US government official on exiting.Just last September I crossed into Canada,by foot,and the only government official I encountered was a Canadian Immigration/Customs officer.