I know some peoples in more southern parts of the Americas had forms of written language, however, I was unsure as to whether this is something that had also developed among groups living in modern America-Canada prior to Columbus.
There is/was the Micmac writing system:
Schmidt and Marshall argued in 1995 that the missionary system of the 17th century was able to serve as a fully functional writing system. This would mean that Miꞌkmaq is the oldest writing system for a native language north of Mexico.
Pierre Maillard, Roman Catholic priest, during the winter of 1737–38 created a system of hieroglyphics to transcribe Miꞌkmaq words.
However, as Barry Fell points out, the Micmac hieroglyphics are very similar, in both form and meaning, to the Egyptian ones (America BC, pp. 255, 256).
And then a little mystery (p. 257):