Minority group essay help!?

Minority group essay help!?
I have to write a page essay on minority groups..i’m kind of confused I would just like to know what exactly a minority group is and have a couple examples of minority groups today AND how sociologists look at these groups of people..
Also, I was wondering what this quote means:
“Almost always, the creative dedicated minority has made the world better.” -MLK

blacks / chinese / koreans/ hispanics are minority in usa / uk. being minority they tend to realize that they must excel to ensure that the majority would not trample on them and respect them.
this is usually the case where the majority or those who hold the barrel of the gun controls everything.
in, the few million whites controlled the millions and millions of black by sheer power of arms. killing them etc was common as was in usa till the present times.
look at chinese who are overseas – nearly all of them excel in bizness or something
it really depends on the oppression / opportunities