(read how to identify your stamp below)
You have the 1c Franklin from the years 1870-1879. It is quite common.
If the stamp has an embossed grill (shown below), then clicking here.
If the stamp has no grill then examine the large number one on the bottom of the stamp.
A crescent in the pearl or dot to the right of the number one identifies the later issues.
If you see that tiny crescent in the dot (shown below) then click here. If the stamp has a date cancel and you can see the date is prior to February 3rd, 1879 then click here. All unused stamps belong to the latter period of numbers 182-191.
If you do not see the tiny crescent (shown below) then click here
Lastly if you see the shading above the head being almost solid (shown below) AND the color tends to be more of the greyish blue on the right stamp above AND you also see the tiny crescent on the pearl to the left of the number one, you have the 1881 printing by the American Bank Note Company.
An example of normal shading
This stamp was reprinted in 1875 and it can be viewed by clicking here. These are all accounted for, so you will not own this.