it's a pity that the resolution afforded on the onscreen version doesn't make for reading of some of the smaller notations.
using a jeweler's loupe, I find gems like this, running along the top right, near the northeastern border: "the road the French take to go to Carolina." For a good portion of it, it follows the Acansea River. (I could turn this into more trivia, but I won't)
with googling, I discover that Acansea was what the French called the Ohio, and is from the word that led to the formation of both Kansas and Arkansas.
<<The spelling of the term [Arkansas] represents a French plural, Arcansas, of a name applied to the Quapaw people who lived on the Arkansas River; their name was also written in early times as Akancea, Acansea, Acansa (Dickinson, 1995). This was not the name used by the Quapaws themselves, however. The term /akansa/ was applied to them by Algonquian speakers; this consists of /a-/, an Algonquian prefix found in the names of ethnic groups, plus /kká:ze, a Siouan term refering to members of the Dhegiha branch of the Siouan family. This stem is also the origin for the name of the Kansa tribe and of the state of Kansas; thus the placenames Arkansas and Kansas indirectly have the same origin. [William Bright, "Native American Placenames of the United States," 2004]>>