Already posted but for those that can't READ or Comprehend here it is again:

Carrying Cash During Air Travel:
There is no limit to the amount of cash that may be carried on any flight, either domestic or international or any other means of crossing the border. The people who are saying that there is a limit on international flights or international travel of any means are not correct -- for international travel arriving in or departing from the US, you may carry as much cash as you'd like; however, any amounts in excess of $10,000 must be declared to US Customs either upon departure or upon arrival.