As Americans Handle $1 Bills Frequently,

I am guessing they know how the original 13 state are represented on $1 bills,

photo credit: Public Domain / Wikimedia Commons, but for the rest of us whilst the all-seeing eye on the $1 bill is universally recognizable, many of us non-Americans would be surprised to learn the banknote also pays homage to the original 13 colonies, along with the 13 steps climbing the pyramid, the denomination features 13 vertical and horizontal bars and stripes on the shield, and 13 stars above the eagle, it doesn’t stop there, 13 berries and leaves appear on the olive branch held by one of the eagle’s talons, while the other holds 13 arrows, finally, there are 13 stars on the Department of Treasury seal, have I missed any more?

but why the green ink? a $10 Virginia Treasury Banknote 1862 (Photo Credit: Keatinge & Ball / Wikimedia Commons), it was used to stop counterfeiting, we have to go back in time, as cameras at the time could only take photos in black and white, in order to prevent the counterfeiting of bills, the government printed them in green ink, and green ink continued to be used after denomination designs became standardized in 1929, simply because there was so much of it! For an explanation of the ‘greenback’ have a look here.