Black Americans have been in something like a permanent state of identity-crisis, that will probably not abate until either:
Terms like "African-American" are accepted as fully and as un-ironically as "Polish-American" or "Irish-American", or;
Race itself becomes such a nebulous, blended, and indistinct thing that skin-color is regarded as no different from eye or hair color.
In the meantime, a particular challenge for black Americans is disconnection from historic familial roots. An Irish-American family might name their kid Sean or Daniel or Molly or Colleen or Mary, with some connection to those who came before (even if those names might bear little or no resemblance to ancient Irish names and culture).
Most black Americans bear family names from the slave-owners of their forbears, or arbitrary names given to freedmen. A white American man named, say, Robert DiGiacomo might go by "Bobby", and might consider himself mostly German/Scots, but he knows where his name comes from, and he knows that his father was descended from an Italian. If he wanted to, Bobby G could probably trace his ancestry back to specific people and families from any number of countries.
A black man named Robert Smith might have little more than a vague idea that one of his ancestors was once owned by a man named "Smith". It is unlikely that he could reliably trace most of his family tree back further than slavery, since good records were not kept, about the lineage and ancestry of slaves. And any "deep past" records of his roots might actually refer to white parentage that abandoned or rejected their multi-racial offspring. He might not be able to able to find the specific African language, name-tradition, or region his ancestors came from, even if he tried.
As a result, many Black Americans have chosen to embrace an entirely new notion of heritage and identity, based on the global infusion of African culture into a worldwide diaspora. This could include elements of Caribbean, Creole, French-colonial, and Anglo-American influences, as well as pan-African culture (and Africa is a very big place, with wildly-divergent cultures, easily as different as Irish is from Greek, or Japanese is from Indian).
One example of this embrace of Black pan-culturalism is choosing or creating names that might sound exotic in any language. People who know the names of their ancestors might choose names that come from the same tradition. But when you don't know the names of your ancestors, or when you know their legal names to be "fake" names given to them by the people who bought and sold them like chattel, it's not so easy.
If you know something vague of where you came from, and that you are part of a diaspora that has influences the world over, you might choose to give your child a name that reflects that uncertain melding of cultures.
Indian parents might name their kids "Vijay", Swedish-Americans might name their kids "Gustav", Japanese might name their kids "Haruto", Italian-Americans might go with "Antonio", etc...
But Black Americans descended from the nebulous heritage of slavery have no obvious tradition of forefathers to turn to, when it comes to naming their children, except maybe slave-names.
So many choose to invent or adopt new names, as the ancients did in other cultures. Just as names like "Antonio" or "Robert" or "Seamus" were once invented and applied to children, so names like Leshawn or Taniqua are invented or adopted by people who are not without a culture, not without a heritage, just without a fixed vocabulary, due to its newness.
The African diaspora has had a massive global influence on culture, but it happened in very different ways than other historically-recent diasporas. We were not around 1,000 or 10,000 years ago, when the Europeans or Africans were first inventing names.
In the great re-combinator that is global cultural evolution, Black America has emerged as a new distinct cultural tradition, much as Celts and Gauls diverged and became things like Scotch, Irish and German, hundreds of years ago.
The culture of "Black America", and of the African diaspora more generally, is still in its infancy. We're still in an era where people who lived under Jim Crow are alive and kicking, and the last slaves are only a few decades dead.
As people with names like Kanye, Obama, and Deshawn become more prominent and influential participants in the global economy of ideas, their names will begin to sound less strange. We are seeing the emergence of a new global cultural tradition, with ethnic and historical influences that are distinct from the existing ones.
Black American culture has a very troubled and difficult past, and much of it still has a troubled and difficult present, but its present is no worse than that of, say, the Irish from 150 years ago. ("How the Irish Became White" is an interesting read on the topic of historical race-identity).
Black America, and the African Diaspora more generally, is still in the process of inventing itself, as a cultural identity. And that includes names. It has contributed a tremendous amount of good to the world in its early days, and there is no reason to think it won't get better.
edit: wow, RIP inbox, and thanks for all the gold!
To address some of the FAQs:
"Obama isn't a made-up name! And it's a last name!": Yes, I meant that as more people adopt it as a first name, and as more names that sound "black" come into prominence and familiarity, they will start to sounds less exotic or strange. Sorry for the ambiguity.
"I don't think anyone really calls themselves 'Irish American' or 'Polish American'. Everyone is just American." There are thousands of Irish-American, Polish-American, Italian-American, German-American clubs, all across the US. So it is definitely a thing for some people, although maybe not for you.
"I disagree with the term 'African Americans', because it's not an accurate term, or something about hyphens." You're right, it's not an accurate term. Neither is "black" or "white" (that's more like a dark-brown to pinkish spectrum). I try to use words with commonly-accepted meanings, as they are commonly understood. Unfortunately, sometimes we use short words to refer to complex or nuanced ideas such as race and ethnic identity, and it can be hard to discuss anything other than the verbiage and nomenclature itself, without adopting some kind of shorthand that someone is bound to find objectionable.
" 'Scotch' should be used for whisky and tape, not to describe people." Sorry, I stand corrected. Error left as posted, for continuity-purposes.
A lot of other posters have raised a lot of very good and interesting points, and others have raised a lot of bad and long-discredited ones. I am grateful if I was able to help spark interesting discussion.
