The March of Washington took place on August 28, 1963, in front of the Lincoln Memorial. At the March of Washington, Martin Luther King Jr. gave his famous, "I have a dream" speech. The march happened to raise awareness of the challenges for African Americans trying to get a job.
The movement needed funding in order to get the speakers to Washington DC and to bail people out of jail if necessary.
It was thought that the march might make it harder for the Civil rights legislation to be passed. This made them need for the march to go perfectly so that they had no reason to not pass it from the march.
They wanted for the march to be a huge march so that it would get lots of attention, For this reason, they needed lots of people to be willing to participate.
The march on Washington was a peaceful march. They were not violent and they used speaking to fight for their rights.
The march of Washington was attended by many people. Because of this, It was publicized more as it was a big protest, so the cause they were fighting for was documented everywhere making lots of people hear about the cause.