The bottom line is, yes, there was definitely a racist root to much of it. One of the concerns of the Supreme Court in the infamous Dredd Scott case was that if blacks were citizens, then it would give, horror of horrors, "to persons of the negro race ... the full liberty of speech ...; to hold public meetings upon political affairs, and to keep and carry arms wherever they went." You can imagine how well the concept of armed blacks went over down South.

Fortunately, there were plenty of laws on the books prohibiting certain people from being armed, such as one to "prohibit any negro or mulatto from having fire-arms.", as addressed by the deliberation for the Civil Rights Act 1866. For more details on the problems occasioned by the 14th Amendment and the fact that the white government could no longer blatantly say that blacks couldn't have guns, check here. http://www.guncite.com/journals/senhal14.html

As a result, modern gun laws came to be crafted a little more creatively. If it was unconstitutional to blatantly say "Whites can carry guns, blacks can't", then they had to find more ethereal ways around it. For example, laws on the carriage of concealed weapons could be...discretionary. California's current one is a case in point. The San Francisco Chronicle article on the matter back in 1923 (available about half-way down this PDF http://www.hoffmang.com/firearms/AB263-Hawes-1923.pdf ) is quite open about how the law was carefully crafted to try to avoid unConstitutionality issues. The target in this case was not blacks, but Asians and Latinos. The still-extant law requires that the Sheriff decide that the applicant for a firearm show 'good cause' and 'be of good moral character', a very subjective assessment which, back in the days, effectively meant 'you're white', but today the application of the law has gone more to a race-neutral position based on whether or not the Sheriff likes the idea of an armed private citizenry.

Of course, not all gun control laws were racist. For example, back in the day, it was considered that carrying a firearm concealed was the act of a scourge and scoundrel, and that honest gentlemen carried them openly, this applied to all regardless of race.