Past Self-censorship on the Tulsa Massacre?

There is much discussion today about the Tulsa Massacre of 1921, including talk about why so few Americans were even aware of it until recently, and even fewer were aware of its scope and significance.

In response to the upheavals of the late 1960s, my alma mater, the George Washington University, offered in 1969 History 174, The Negro in American History; the professor used eminent African American scholar John Hope Franklin's From Slavery to Freedom: A History of Negro Americans (3d edition) as the textbook. I took the course. I still have the 652-page book. Today, I went to the index to see what was written about the Tulsa Massacre. Much to my surprise, the entire discussion is in one part of one paragraph (pp. 483-84). The details and huge significance of those horrible days were treated cursorily by Professor Franklin as nothing more than a denouement to a series of incidents of mob violence in the United States in 1919. Here is the passage:

[I]n June 1921, the Negroes and whites of Tulsa, Oklahoma, engaged in fighting which some residents prefer to call a ‘race war,’ in which 9 whites and 21 Negroes were known to have been killed and several hundred injured. When news reached Negroes of the accusation of an assault of a young woman by a Negro, Negroes took arms to the jail to protect the accused person, who, it was rumored, would be lynched. Altercations between whites and Negroes at the jail spread to other parts of the city, and general rioting, looting, and houseburning began. Four companies of the National Guard were called out,, but by the time order was restored more than one millions dollars worth of property had been destroyed or damaged. This progressive young city of the Southwest was thus added to the list of communications in which there was no interracial peace.

This description is even more surprising in light of the fact that Professor Franklin’s father was attorney Buck Franklin, who, according to Wikipedia, is “best known for defending African-American survivors of the 1921 Tulsa race riot, in which whites had attacked many blacks and buildings, and burned and destroyed the Greenwood District. This was known at the time as the 'Black Wall Street', and was the wealthiest Black community in the United States, a center of black commerce and culture.” 

Is part (albeit a small part) of our national ignorance the fear of African American scholars of being too forthcoming regarding the depth of American racism, for fear of being written off as too sensitive? I do not know. But it is something worth considering.