The Montgomery Improvement Association (MIA) was formed on 5 December 1955 by black ministers and community leaders in Montgomery, Alabama. Under the leadership of Martin Luther King, Jr., the MIA was instrumental in guiding the Montgomery bus boycott, a successful campaign that focused national attention on racial segregation in the South and catapulted King into the national spotlight.

Following the arrest of Rosa Parks on 1 December for failing to vacate her seat for a white passenger on a Montgomery city bus, Jo Anne Robinson of the Women’s Political Council and E. D. Nixon of the National Association for the Advancement of Colored People (NAACP) launched plans for a one-day boycott of Montgomery buses on 5 December. Ninety percent of the black community participated and stayed off the buses that morning, and, at an afternoon meeting of local black leaders, the MIA was formed to continue the boycott. These leaders also elected King, then beginning his second year as pastor of Dexter Avenue Baptist church, to serve as MIA chairman. At an evening meeting attended by several thousand community members, King and other newly-selected leaders affirmed that the MIA's objectives were not only to continue the boycott but to "improve the general status of Montgomery, to improve race relations, and to uplift the general tenor of the community."

After the MIA’s initial meeting, the executive committee drafted the demands of the boycott and agreed that the campaign would continue until demands were met. Their demands included courteous treatment by bus operators, first-come, first-served seating, and employment of Negro bus drivers. Over the next year, the association organized carpools and held weekly gatherings with sermons and music to keep the black community mobilized. Also during this time period, MIA officers negotiated with Montgomery city leaders, coordinated legal challenges with the NAACP to the city's bus segregation ordinance, and supported the boycott financially, raising money by passing the plate at meetings and soliciting support from northern and southern civil rights organizations.

The boycott ended in November 1956 when the U.S. Supreme Court affirmed Browder vs. Gayle and struck down laws requiring segregated seating on public buses. King emerged as a national figure, and the MIA's tactics became a model for the many civil rights protests that would follow. The Montgomery victory affirmed the potential for mass-based nonviolent resistance to successfully challenge and transform segregation.

Following its success in Montgomery, the MIA became one of the founding organizations of the Southern Christian Leadership Conference (SCLC) in January 1957. The MIA lost some vital momentum after King moved from Montgomery to Atlanta in 1960, but the organization continued campaigns throughout the 1960s, focusing on voter registration, local school integration, and the integration of Montgomery parks.

Mary Fair Burks, "Trailblazers: Women in the Montgomery Bus Boycott," in Vicki L. Crawford, Jacqueline Anne Rouse and Barbara Woods, eds., Women in the Civil Rights Movement (Bloomington: University of Indiana Press, 1990)

Clayborne Carson, Stewart Burns, Susan Carson, Peter Holloran & Dana L. H. Powell, eds., The Papers of Martin Luther King, Jr., Volume III: Birth of a New Age, December 1955–December 1956 (Berkeley: University of California Press, 1997)

Clayborne Carson, ed., The Autobiography of Martin Luther King, Jr.(New York: Warner Books, 1998)

Martin Luther King, Jr., Stride Toward Freedom: the Montgomery Story (New York: Harper & Row, 1958)

Aldon Morris, The Origins of the Civil Rights Movement: Black Communities Organizing for Change (New York: The Free Press, 1994)

Howell Raines, My Soul is Rested: Movement Days in the Deep South Remembered (New York: Puttnam, 1977)

Jo Ann Robinson, The Montgomery Bus Boycott and the Women Who Started It (Knoxville, Tennessee: University of Tennessee Press, 1987) "MIA Mass Meeting at Holt Street Baptist Church," 5 December 1955

"To the Montgomery Public," advertisement submitted by King and the MIA to the Sunday Advertiser and Alabama Journal, 25 December 1955

King’s address to MIA Mass Meeting at Day Street Baptist Church, 26 April 1956

King’s address to MIA Mass Meeting at Holt Street Baptist Church, 14 November 1956