12USC411 does not exist.

[allodial]

...a. Federal Reserve Notes. Most people mistake the Federal Reserve Note (FRN) “dollar bill” for a “dollar.” But no statute defines or ever defined the “one dollar” FRN as the “dollar” or even a “dollar.” Moreover, the United States Code provides that FRNs “shall be redeemed in lawful money on demand at the Treasury Department of the United States . . . or at any Federal Reserve bank.”3Thus, if FRNs are not themselves “lawful money,” they cannot be “dollars,” the units in which all “United States money is expressed.”

It might make more sense in view of each Federal Reserve Bank being a clearinghouse and the FRN being a clearinghouse certificate with the 'cashout' and local currency of that clearinghouse being U.S. dollars. The confusion in the United States being a term or name for both a singularity called "the United States" and also for a plurality of states is another issue. The FRNs are for banks in 'the District'--this is made clear.

What do you do when you leave the Casino? You exchange your chips for 'real money' (i.e. you redeem them).