1898 Trans-Mississippi: Mississippi River Bridge $2 Orange Brown
This stamp shows a bridge over the Mississippi River. It is part of the Trans-Mississippi set.
Transportation
1869 SS Adriatic 12c Green
This pictorial shows the SS Adriatic. I do not own this stamp yet. It is here courtesy of the Wikimedia Commons.
1893 Columbian Exposition: Santa Maria 3c Green
This stamp commemorates Columbus by showing a likeness of his flagship, the Santa Maria. Note: I do not own this stamp yet. It is here courtesy of the Wikimedia Commons.
1869 Train 3c Ultramarine
This stamp shows a locomotive used to transport both people and mail in its day.
Steel Plant 25c Carmine Rose
This parcel post stamp shows a steel plant.