What you have is known as a National Bank Note. Series 1929 Nationals come in two types: Type 1's came in a sheet of 6 notes with the same serial number but different plate positions. Type 2's were also issued in a sheet of 6 however each note carried a sequential serial number (e.g. 1,2,3,4).
CoinFrog is correct that Type 1 small size nationals are common compared to Type 2's.
-MV