Falling in the tradition of the Hebrew prophets King frequently drew attention to matters of money, poverty and economics. "I Have A Dream" is fairly subtle and limited in it's discussion of economic inequality - compared to many of his other speeches King was more cautious as he made use of this opportunity to reach out to white middle-class Americans - but it's there nonetheless.
The Globe and Mail has a good commentary on the full text of the speech here which highlights the context for a number of things that King references in the speech. Here's one of the comments on what King had to say about poverty and economics:
"One hundred years later, the Negro lives on a lonely island of poverty in the midst of a vast ocean of material prosperity."
King emphasizes that the march was not just for civil rights—its full title was the “March on Washington for Jobs and Freedom.” He told reporters that the march had a dual purpose: “to arouse the conscience of the nation on the economic plight of the Negro 100 years after the Emancipation Proclamation and to demand strong forthright civil-rights legislation.”
This is the key area where both the United States and Canada still fall far short of King's dream. The most overt forms of racism and discrimination have largely become socially unacceptable in both countries even though they still occur in various forms. On the whole we don't usually see segregation and violence or hear racial slurs on a day to day basis, thought of course this depends where you live in both the US and Canada (and as a Canadian I'd say we're generally better on this than our American neighbours). But when it comes to the poverty and economic injustice suffered by not only those of African descent but many other visible minorities in either country, these injustices are blatant, deep rooted and enduring.
Here in Canada we need only look at the poverty, social problems and violence that afflicts many predominantly black neighbourhoods in Toronto - among those whose families have been here in North America for generations as well as among more recent African and Caribbean Canadians. Or we can look as the terrible conditions on countless First Nations reserves across the country and the poverty and violence in urban areas with large Aboriginal populations like the Winnipeg inner city. There are many more places and people whose unjust poverty could be named. And the shameful thing is that it is still minority groups that suffer disproportionately from poverty as well as the intimately related blights of illness and crime.
Where discrimination particularly comes into play is the callous comments made so often, sometimes quietly or in private and at other times publicly or in print - "Well it's their own fault;" "They need to take responsibility for their own lives;" "Go and get a job and stop complaining". Contrary to what some believe, history powerfully affects present and where and to whom you are born makes a huge difference in life. Historic injustices do not disappear overnight, affect generation after generation, and can only be faced when we as a society take collective effort to try to set them right.
Martin Luther King Jr. said as much in a speech he gave on April 4, 1967 protesting the Vietnam War:
"A true revolution of values will soon cause us to question the fairness and justice of many of our past and present policies. On the one hand we are called to play the good Samaritan on life's roadside; but that will be only an initial act. One day we must come to see that the whole Jericho road must be transformed so that men and women will not be constantly beaten and robbed as they make their journey on life's highway. True compassion is more than flinging a coin to a beggar; it is not haphazard and superficial. It comes to see that an edifice which produces beggars needs restructuring."
At it's core Dr. King's dream was the Kingdom of God, something we'll never fully claim until Jesus comes again. But in the meantime we are called by our Lord to bring as much of that dream into reality as we are made able to by the Spirit of God. King called this work 'letting freedom ring.'
"When we allow freedom to ring, when we let it ring from every village and every hamlet, from every state and every city, we will be able to speed up that day when all of God's children, black men and white men, Jews and Gentiles, Protestants and Catholics, will be able to join hands and sing in the words of the old Negro spiritual, 'Free at last! free at last! thank God Almighty, we are free at last!'"