Here is the official appraisal of how Nigerians (and other Africans) are doing in the US, education and otherwise:
“Compared with the overall foreign born population, the foreign born from Africa had higher levels of educational attainment (Figure 6 of the attached full report).High levels of educational attainment among the African born are in part due to the large number of educated Africans who have chosen to emigrate and to many who come to the United States to pursue academic studies.14,15 Forty-one percent of the African-born population had a bachelor’s degree or higher in 2008–2012, compared with 28 percent of the overall foreign born. Egypt (64 percent) and Nigeria (61 percent) were among the African countries of birth with the highest proportion of bachelor’s and higher degrees.
“Nearly one-third of the overall foreign-born population (32 percent) had less than a high school education. This contrasts with only 12 percent for the African-born population, as represented by such countries as South Africa (3 percent), Nigeria (4 percent), and Egypt and Kenya (each 5 percent).”