racial epithets

[Mullins, Bill]

high yellow -- HDAS has 1923, OED has 1951
"At the Theatres" | Nebraska | Lincoln | The Lincoln Daily Star |
1916-06-22 p. 3. col 3.
"They present the typical minstrel nigger and high yaller octoroon."

"Honey Boy" Minstrels Please Large Audience at Atlanta
The Atlanta Constitution; Mar 12, 1915; pg. 12 col 3.
"Eldon Durand is a classic in make-up in his part of the Miss Flooeyanna
Wilkins, the "high yellow," for whose charms "Lasses" inevitably falls."

blue gum -- not in OED nor HDAS, as near as I can tell

THE MAGIC CHARM
The Atlanta Constitution; Oct 18, 1891; pg. 11 col 3.
"Their bite is as bad as a blue gum nigger."

"BLUE GUM NEGROES"
Ohio | Lima | The Times Democrat | 1897-07-23 p. 7 col 4.
"Among the numerous superstitions of the old plantation days which still
linger in the south none is more pronounced or more widely diffused than
the belief in the fatal effecs of the "blue gum nigger's" bite." "

[I had heard "blue gum" as an epithet for AA for years, usually taking
it to mean "a black person whose skin is so dark their gums look blue in
comparison".  But I've never heard this business about the bite of a
blue gum.