1-2 paragraph about the purpose of Dr.King's I have a Dream Speech , and why it was important and still important today?

The purpose of Dr. Martin Luther King Jr.'s speech was at least twofold: it was an integral part of the August 28, 1963 march on Washington, DC for the realization of economic and civil rights for blacks, and it provided much-needed support for civil rights legislation that President John F. Kennedy had proposed to Congress two months prior, in June. 
The speech was important in 1963 because the country was still legally segregated.  It was not until the Civil Rights Act of 1964 that it became illegal for state and local authorities to segregate Americans on the basis of their race. Because blacks had no federal protection, they were denied access to schools, businesses, and other organizations because of their race. Moreover, discrimination was holding black people back from equal access to jobs. King's speech was a call to follow through on the promises of the Emancipation Proclamation one hundred years before and the Declaration of Independence's claim that "all men are created equal."  King refers to these seminal documents along with the Constitution to point out that American blacks were denied many of the basic human rights that their citizenship guaranteed for them.
The speech is still important today because it reminds us that in America, the promises our government makes in its founding documents are not always carried out for all people.  Though blacks have legal protection from discrimination, America still has social problems centered on race. Evidence used to support this argument include findings that blacks are incarcerated at higher rates than other races and are treated unfairly by police and the judicial system. Blacks applying for mortgages and other loans find it more difficult to borrow. Unemployment  and poverty rates are higher for African Americans than for other races. The Black Lives Matter movement was founded after the murder of a black teenager and subsequent acquittal of his killer. It labors to move black Americans forward in American society. 
Though the Civil Rights Act was passed in 1964 and America elected its first black president in 2008, many of the inequities Dr. King cited in his speech continue to trouble America. The "I Have a Dream" speech reminds Americans of the continued work required to deliver social justice to all Americans.