Originally Posted by
GoingAway
As far as the tax implications, why is everyone harping on that aspect as the OP said they pay taxes, and there is nothing wonky about the funds.
Agree - Although part of the purpose of the rule is to avoid tax cheating. Of course, with a form saying you brought $10000 in cash into the US there's some chance if that income doesn't show up in your tax return you could be in trouble.
But the primary purpose of this rule is to prevent money laundering. If you repeatedly bring in loads of cash, CBP may want to start asking some more questions. Since the OP seems to have good answers, it shouldn't be a problem.