The US $100 bill from the pre-1860s to the newest of them.
Mark Wagner makes these stunning collages out of $1 bills. Be sure and check out his mega-collage called Liberty.
From the Artist Statement:
The one dollar bill is the most ubiquitous piece of paper in America. Collage asks the question: what might be done to make it something else? It is a ripe material: intaglio printed on sturdy linen stock, covered in decorative filigree, and steeped in symbolism and concept. Blade and glue transform it-reproducing the effects of tapestries, paints, engravings, mosaics, and computers—striving for something bizarre, beautiful, or unbelievable... the foreign in the familiar.