If you listed the place of registration as New Orleans, Louisiana, then it most definitely would not have been a lie. As far as the antebellum South goes, they were the best as far as having free blacks goes, and they had alot of them. Most of the black pro-Confederate militias organized during the war were drawn up in the New Orleans area, and they consisted of free blacks who had something to protect.
You may or may not be familiar with Mount Vernon, Alabama. All you need to know is, it is black, everyone up there is distantly related, most of them have some French blood in them, and, this is the kicker, they are descended from a family of blacks who not only held slaves, but ran major plantations within the area. Incidentally, a major black Catholic in-church social fraternity was founded by these people.
Let's not forget, many masters would give their slaves manumission in their wills, and those that didn't, well, more often than not, in their wills, they would leave instructions that would effectively allow their slaves to live as if they were free, often times, this included a large amount of money, and executors were bound by law to carry out these instructions. And, as I alluded to before, there were certain areas in the South where there were concentrations of free blacks.
If that were so then the southern states must have just been swimming in free blacks. But a check of the census records shows that just wasn't so. Alabama had 438,000 black persons, 99.4% of whom were slaves. Mississippi had 773 free blacks, down from the 1850 census. Arkansas had 144, also down from the prior census. Louisiana had more free blacks in 1830, over 25,000, than they had in 1860, less than 19,000. If manumission were as free and open as you claim then these figures couldn't be true.