About 175 persons, mostly students and mostly black, marched from the Rackham Building to the Diag on the University of Michigan's central campus late this morning. The march was peaceful and well-organized, and demonstrators wore Black Action Movement III badges vowing they would "continue the struggle" for equal rights at the U-M. Some marchers carried signs saying "Black power is real power and "Put an end to racist ideals." A tape recording of a speech by the late Martin Luther King Jr. was played as the march went on.