The Great Migration
With a new city promising multiple jobs to be available, this prompted many African Americans to come to Gray during the Great Migration. By 1919, Gary had 20,000 residents that were foreign-born. Also by then there was a polarization in the city that had people join the Ku Klux Klan. Early 1920s Indiana had an estimated 350,00 members. Racial tensions and poor wages help lead up to the strike of 1919. Strikes were happening nationwide, and the one in Gary lead to a riot. It was shut down by 4000 troops, 3 days later.
The 1920s brought Gary many profitable years. From the mills producing steel to Broadway begin a commercial hub. But the numbers of minorities were rising (53% in 1970) and Whites were slowly leaving. The change in population caused a change in politics.

The later on in the 20th century

As Black Americans grew in population they wanted to achieve more power in the political, economical, and social parts of the city. This lead to many school skies about mistreatment and the Rise of Richard Hatcher .
Here is a snippet from the book "City of the Century" describing Hatcher's first year.
Hatcher's first year in office was marked by labor disputes involving police, firemen, garbage collectors, and social workers and several near riots. After the assassination of Martin Luther King, Jr. about 200 students stormed out of school. Soliciting help from the Roosevelt championship basketball team, Hatcher persuaded them to return to classes. Three days later, he closed schools for a day of prayer and mourning. A year after King's death, Hatcher paid tribute to the slain leader, saying: "He represented a kind of order-to use a dirty word-in the civil rights movement, a kind of reasonableness and willingness to forgive people that maybe a Rap Brown or an Eldridge Cleaver would not have."
Several weeks later, a downtown fire precipitated incidents of rock throwing and minor looting which resulted in 127 arrests. Hatcher visited the scene, alerted the National Guard, imposed an after-dark curfew, and met with some of the gang leaders rumored to be involved in the trouble.
In May 1968 the Concerned Citizens for Quality Education (CCQE) organized a week-long school boycott involving 20,000 students in protest against the alleged segregationist policies of Acting Superintendent Clarence E. Swingley. An antiboycott group, the Citizens to Save Our Schools (CSOS), then vowed to march on City Hall. Warned that black gangs were ready to attack the CSOS demonstrators, Hatcher convinced CCQE organizer Steve Morris, a clerk in the school lunch program, to call off the boycott, thereby avoiding the confrontation. Hatcher later appointed Morris to a CEP staff position and defended the school boycott as an example of "our community speaking to us, loudly and clearly, about the need to... reorder our priorities on the educational scene."
In the fall of 1968 six youths mugged and robbed a Serbian priest. A delegation from St. Sava Orthodox Church demanded a City Council.