This weekend marks the 50th anniversary of the March on Washington and MLK's "I have a dream" speech (with scenes of marching). Above is a short (4:31) interesting 60 minutes interview with MLK where is discusses why he favors peaceful demonstrations.
John Hiltz sent me the video below of people marching on DC in August 1963 (two months before I was born!). Here are some personal recollections you could use with your students.
For those of you who like old "clippings," here is the NYTimes from August 29th and here is the WashPost.