Today we take advantage of the fact that we can create multi-colored graphs with a few clicks of a mouse. Prior to computers though, graphs had to be hand drawn and colored. It can be clearly seen that colored pencils were used to fill in the various parts of the graph below. Note the small spaces where the creator accidentally colored outside the lines! Ooops! One thing that is especially impressive about this graph is how vibrant the colors still are even after over 70 years!
Series: All-American Canal Project Histories, 1948-1954. Record Group 48: Records of the Office of the Secretary of the Interior, 1826-2009. National Archives Identifier: 2292770