Ben de la Cruz, Walter Ray Watson, Nicole Werbeck, Pearl Mak, Keith Jenkins/NPRYouTube Fifty decades ago, photographer and folklorist Roland Freeman hitched his hopes to your humble caravan of mule-driven wagons. The Mule Practice remaining the small town of Marks, in the Mi si sippi Delta, for Washington, D.C. It was component of Martin Luther King Jr.'s previous major effort to mobilize impoveri...