Brainerd, Minnesota. $20 1882 Brown Back. Fr. 504. The First NB. Charter #2590. PMG Choice Fine 15.This 1882 $20 Brown Back is one of just two Brown Backs known from this Crow Wing County bank. The First National was chartered in 1881 and issued $702,720 in large and small notes through the end of the National Currency era in 1935. Well penned signatures and still boldly inked design elements are seen on this example. PMG notes Minor Repair, Trimmed on the back of the holder.