refusing to hire

Is My Employer's Conduct Considered Unlawfully Discriminatory?

I am African-American and have been working for my employer for 3 years. Many new people have been hired over time, White, Latino and some African-Americans. It seems like the managers in the store are all White. I have applied for a Manager position a few times and have been told "No" in a very friendly way, but I have more experience than most of the people that get management positions.