Do immigrants need passports to go abroad and return home?

I also entered the United States on an immigrant visa.

I got a green card about a month after I came to America.

When you go through the customs before entering the United States, the customs should stamp your passport and write down a series of numbers. This is your green card number.

I remember that if the green card holder leaves the United States for more than six months without a return permit from the United States, it seems that the customs here in the United States can question whether you really want to immigrate to the United States, and you may receive your green card, and then you need to go to court to explain.

In fact, you can apply for an American card before you get a green card.