Badge714 is right. Your new girlfriend is a guy in Nigeria. "She" wants to come to the US to marry you. You have to send her money to pay for the plane ticket. Which she will spend on something else.
"She" has quite a few boyfriends, all falling for the same scam.
It's more likely the "girl" you met is a Nigerian man sitting in an internet cafe. You can be sure at some point you would be asked for money. This, of course, is right after your "girl" tells you, after knowing you for an hour, that she is madly in love with you, you're here soul mate, & wants to travel to get married. Where does the money come in? During travel "she" would (1) Be robbed at the hotel, losing all her money (2) A 'fee' at the airport (3) Car broke down. In all these situations the common thread is "Western Union", or "Money Pak", or any other form of wire transfer. Better known as CASH.
Badge714 is right. Your new girlfriend is a guy in Nigeria. "She" wants to come to the US to marry you. You have to send her money to pay for the plane ticket. Which she will spend on something else.
"She" has quite a few boyfriends, all falling for the same scam.