TEMPE, Ariz. – Dr. Martin Luther King Jr.’s voice echoed throughout Tempe Diablo Stadium.

His famous “I Have a Dream” speech could be heard in the bullpens while fastballs pounded mitts. It provided the soundtrack during batting practice on the main field where Mike Trout spends his spring. The powerful words boomed all the way to the backfields deep in the Minor League complex where instructors Mike Scioscia and Ron Washington ran the teens through drills.

“I say to you today, my friends, so even though we face the difficulties of today and tomorrow, I still have a dream. It is a dream deeply rooted in the American dream.

I have a dream that one day this nation will rise up and live out the true meaning of its creed: "We hold these truths to be self-evident, that all men are created equal."

I have a dream that one day on the red hills of Georgia, the sons of former slaves and the sons of former slave owners will be able to sit down together at the table of brotherhood.

I have a dream that one day even the state of Mississippi, a state sweltering with the heat of injustice, sweltering with the heat of oppression, will be transformed into an oasis of freedom and justice.

I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character. I have a dream today.

Dr. King’s vision was the inspiration for the fourth annual Dream Series that concluded Monday and his message of hope, equality and longing for a better future hit home with the 80 baseball dreamers in attendance. The program, which is run by MLB and USA Baseball in connection with Martin Luther King Jr. Day, is focused on developing and diversifying the talent pool in the sport. It is designed to make better baseball players and show the prospects how to succeed on and off the field. It is also about much more.

“As we remember his birthday each year and the weekend and his 'I Have A Dream' speech, we allow the kids to listen to some of his speeches, but really allow the kids to leave with the inspiration of achieving their dreams and realize that his 'I Have a Dream' speech is about these kids,” said Del Matthews, MLB's senior director of baseball development. “They’re the living proof of what he had a dream for. We inspire the kids, we teach them about their history. Dr. King, probably one of the most important African-Americans in African-American history. It’s great to have this event for Dr. King. We’re excited to be able to celebrate it in his name.”

The event began Thursday with a welcome dinner and featured daily instruction on the field. The program also featured study halls and presentations on baseball career opportunities at the professional and collegiate level. Pirates pitcher Chris Archer was among the guest speakers. The Dream Series also featured athletic assessments through Prospect Development Pipeline (PDP) screenings.

“Dr. King changed the world and we are cognizant of that,” said Tony Reagins, MLB's executive vice president of baseball and softball development. “We make sure we communicate it at a number of different levels, whether we implement it at batting practice or talk about it in meetings, or get their input in meetings as to what they think about Dr. King. We try to connect all of that into this entire program. We know that none of us in this program would be where we are if it had not been for Dr. King.”

The four-year program already has a history of success. Of the estimated 150 players who have participated in the first three Dream Series events, 25 were selected in the 2017-19 MLB Drafts, including highly touted prospects Hunter Greene (Reds' No. 1), Kumar Rocker (Vanderbilt), Simeon Woods Richardson (Blue Jays' No. 6) and Mike Harris (Braves).

Forty-four participants in this year’s Dream Series have already committed to play collegiately, a list that includes Chase Davis (University of Arizona), who ranks No. 64 on MLB Pipeline’s Top 100 Draft Prospects list, No. 87 right-handed pitcher Markevian Hence (University of Arkansas) and Michael Brown III (University of Washington), a first baseman from California. This year’s group also featured Marquis Grissom Jr. and Andruw Jones Jr., the sons of former Major League stars, who have committed to Georgia Tech and Vanderbilt, respectively.

Among the many highlights on this year’s Dream Series rosters were four sets of brothers. Jared and Jordan Lewis, T.J. and Jordan McCants, Trevell and Termarr Johnson along with Andrew and Andreaus Lewis are proof the sport is reaching families and diverse communities across the country.

“It was a great experience to get out and just getting to know some of the staff, just showcasing your talent with them,” said Jared Lewis, a shortstop. “There’s not a lot of brothers in this game, and there are not a lot of African-American brothers in this game, so we try to influence other kids like us to come out and compete.”

The hope for the staff of the Dream Series is that players like the Lewises, McCants, Johnsons and others will end up in the big leagues or with successful careers off the field. It’s their goal to make dreams come true.

“We’re making inroads. You can’t reap and sow in the same season, so we will see a lot of the fruits of our labor two, three, four years down the line,” Matthews said. “But we’ve got a pipeline, we’ve got kids reaching out to us to be a part of MLB Develops, to be a part of some of the programs we have. We’re going to be here and we’re going to keep reaching and giving them the same message. Hopefully when they grow up four or five years from now, we’ll start to see more numbers in the professional ranks.”