This has been around for a while, although officially it’s been dead and the landing page doesn’t say anything about the 50,000 points, the link still works and you still get the 50,000 points!
The official Link from Citi only offers 30,000 points.
Get 50,000 American Airline miles after $2,500 spend within the first 4 months.
No annual fee the first year.
You may also want to check out the US Airways card, as the points will eventually be converted into American Airline points.
The links below offer 45,000 points (as opposed to the 50,000 above) after $5000 spend within the first 4 months. Additionally, you’ll get a $150 statement credit when you make a purchase on American Airlines, and you’ll also get 2 free AAdmiral lounge passes.