What is ethnicity anyway?
Wikipedia has an enormous list of ethnicities (see links on right). These are in Freebase already but aren't necessarily typed as "ethnicity". Go find one you're interested, hit "Add Type", add "Ethnicity", then fill in the details. Tell us about people of that ethnicity by importing a list -- you can usually find them by googling for "List of X people" where X is the ethnic group. Or, take a list from a foreign-language Wikipedia, or from another website -- either of which may know more about people from minorities than the English-language Wikipedia.
Whether it's your own ethnicity, one you're interested in, or just one you think deserves a little attention, filling it in will help us answer questions like "Which African-American authors have won awards for their work?" or "Show me a list of famous Polynesian people."
When you're done, add the ethnicity you've filled in to "Mobbed Topics", below. Take a look at what's already there for some examples.

