King went to Memphis to support African American garbage workers, who were on strike to protest unsafe conditions, abusive white supervisors, and low wages -- and to gain recognition for their union. Their picket signs relayed a simple but profound message: "I Am A Man." ...
The strike began over the mistreatment of 22 sewer workers who reported for work on January 31, 1968, and were sent home when it began raining. White employees were not sent home. When the rain stopped after an hour or so, they continued to work and were paid for the full day, while the black workers lost a day's pay. The next day, two sanitation workers, Echol Cole and Robert Walker, were crushed to death by a malfunctioning city garbage truck.
These two incidents epitomized the workers' long-standing grievances. Wages averaged about $1.70 per hour. Forty percent of the workers qualified for welfare to supplement their poverty-level salaries. They had almost no health care benefits, pensions, or vacations. They worked in filthy conditions, and lacked basic amenities like a place to eat and shower. They were required to haul leaky garbage tubs that spilled maggots and debris on them. White supervisors called them "boy" and arbitrarily sent them home without pay for minor infractions that they overlooked when white workers did the same thing. The workers asked Memphis Mayor Henry Loeb and the city council to improve their working conditions, but they refused to do so.
On February 12, 1,300 black sanitation workers walked off their jobs, demanding that the city recognize their union (the American Federation of State, County and Municipal Employees, AFSCME) and negotiate to resolve their grievances. They also demanded a pay increase to $2.35 an hour, overtime pay, and merit promotions without regard to race.
For the next several months, city officials refused to negotiate with the union. In private, Mayor Loeb reportedly told associates, "I'll never be known as the mayor who signed a contract with a Negro union."
-Why He Was In Memphis
MLK Jr. Died at a Union Picket Line