$1500 shouldn't have. Hell, you're going through an internal checkpoint, so no amount should have been an issue. If you were at the border, anything north of $9,999 has to be declared, and if it's not, you have a problem. At internal checkpoints, you can carry $100k in unmarked singles in your trunk, and there's not much they can do about it because there's no law against carrying your life savings in small bills in the back of your car.