Possible Clues:

• Civil rights monogram
• Monogram of this puzzle's honoree
• Honoree of a D.C. monument at 1964 Independence Ave
• January holiday inits.
• 58-Across speaker, initially
• 'I have a dream' monogram
• January honoree, for short
• Annual honoree's inits.
• Symbol of equality, briefly
• National b'day honoree