Alternate title: I think these two feasts represent the modern Episcopal Church quite well.
David at In the Agora notes the religious significance of Martin Luther King Day. I would like to note that the Episcopal Church celebrates Rev. King with a feast on April 4, the day of his assassination martyrdom. The collect for the feast is appropriate today:
Almighty God, by the hand of Moses your servent you led your people out of slavery, and made them free at last: Grant that your Church, following the example of your prophet Martin Luther King, may resist oppression in the name of your love, and may secure for all your children the blessed liberty of the Gospel of Jesus Christ; who lives and reigns with you and the Holy Spirit, one God, now and for ever. Amen.
Additionally, Janurary 19 is the feast of Wulfstan, bishop of Worcester 1066-1095. The collect: Almight God, your only-begotten Son led captivity captive and gave gifts to your people: Multiply among us faithful pastors, who, like your holy bishop Wulfstan, will give courage to those who are oppressed and held in bondange; and bring us all, we pray, into the true freedom of your kingdom; through Jesus Christ our Lord, who lives and reigns with you and the Holy Spirit, one God, for ever and ever. Amen.