D.C. - Guns and literacy tests

Another article on the new D.C. registration procedure. The article questions the need for the required written test in order to register a handgun:

Apart from the District's arrogance, what I find most surprising is the absolute silence of the ACLU and NAACP. D.C.'s new registration scheme requires citizens to take a written exam in order to register a gun. Back when those groups actually cared about the civil rights of African-Americans, they objected vociferously to literacy tests designed to keep Blacks, especially in Southern States (run by Democrats) from voting.

According to Wikipedia:

"Literacy Test refers to the government practice of testing the literacy of potential citizens at the federal level, and potential voters at the state level…. As used by the states, the literacy test gained infamy as a means for denying the franchise to African Americans. Adopted by a number of southern states, the literacy test was applied in a patently unfair manner, as it was used to disfranchise many literate southern blacks while allowing many illiterate southern whites to vote. The literacy test, combined with other discriminatory requirements, effectively disfranchised the vast majority of African Americans in the South from the 1890s until the 1960s. Southern states abandoned the literacy test only when forced to by federal legislation in the 1960s."

So now, the government of the District of Columbia is effectively requiring a literacy test to register a gun. A literacy test required in a city that is majority African-American. And the NAACP, ACLU and the civil rights establishment are completely silent. Do any of these groups care about the civil rights of the residents of the nation's capital? It appears not.

In broader terms, why does D.C. require a written exam at all? For what other enumerated Constitutional right does any American have to take an exam? I know of no examination requirement for an American to exercise freedom of speech. No journalist or publisher is required to take an exam to exercise the freedom of the press (although it might prove beneficial). No exams exist as a requirement for freedom of religion, freedom to assemble, or to petition the government for redress of grievances. And that just covers the First Amendment.

Article here. I believe the ACLU is still clinging to its collective rights interpretation of the Second Amendment, so it's not surprising that they haven't voiced concern over literacy testing for exercise of an individual, constitutionally-protected civil right.