Civil rights leader and educator DeRay Mckesson urged the hundreds of graduates at the University of Southern Maine’s graduation ceremony Saturday to change the world.

Mckesson, a 2007 graduate of Bowdoin College, spoke from his experiences as a sixth-grade math teacher at a New York City elementary school and a leading voice in Black Lives Matter. He asked graduates to stand firm in their knowledge and work toward equity, justice and freedom.

“We can’t let people negotiate history. Some things are just wrong,” Mckesson told the crowd at the Cross Insurance Arena in Portland.

The USM graduation ceremony was one of more than a half-dozen held across Maine on Saturday, as commencement season cranked into high gear. Commencement ceremonies took place for six of the seven schools of the University of Maine System and at St. Joseph’s College, the Maine College of Art and Unity College. U.S. Sen. Susan Collins, R-Maine, was the speaker during graduation ceremonies at the University of Maine in Orono, while U.S. Sen. Angus King, I-Maine, spoke at the University of Maine at Presque Isle.

Mckesson delivered his address to the more than 920 undergraduate and graduate students who marched in the USM ceremony, advising them to take a stand against inequality and injustice, and earning several bursts of applause. About 1,400 students received degrees.

In 2015 Mckesson was named one of the World’s Greatest Leaders by Fortune Magazine, and in 2016 one of the 30 Most Influential People on the Internet by Time magazine. Last year, he launched “Pod Save the People,” a podcast on culture, social justice and politics. He is now writing a book, “On the Other Side of Freedom: The Case for Hope,” scheduled for release this fall.

“We have to be OK being honest about (the fact) that there are not two sides to everything,” he said. “There aren’t two sides to homophobia, xenophobia or transphobia. There is a right and wrong.”

Student speaker Lucy Shulman, a linguistics major who is going to Japan to teach English later this year, talked about discovering her own worthiness at USM after entering the university at age 23 without a high school diploma and a nonexistent sense of self-esteem.

“We are significant, and we are worthy,” said Shulman. “And in the years I’ve been at USM, the world has finally seen us. We’re not invisible anymore.”

Shulman told her classmates that their college degrees matter “because we earned them. Everything we put into them, all the blood, sweat and tears, and more tears, and a bunch of energy drinks, are what give us our power.”

Shulman received thunderous applause.

FROM NEAR AND FAR

The stands at the arena were packed with friends and family, many of whom had lined up at the doors before they opened at 7 a.m. for the 9:30 a.m. ceremony. The audience whooped and clapped as graduates marched in procession to their seats while a brass ensemble played in the background.

The O’Hearn family traveled from Florida to watch Jordan O’Hearn, 39, a retired U.S. Navy chief petty officer, receive his master’s degree in leadership studies. Before he moved to Maine to attend USM, O’Hearn had heard great things about the university while visiting Bath Iron Works, which had built the future USS Michael Murphy, the ship he was assigned to, said his friend Brad Gilbert of Turner.

Coco Niyonshuti and Shumbusho David were in Portland on Saturday to watch their sister Aline Uwamariya, 29, graduate. Niyonshuti said her sister came alone to the United States at age 17 from Rwanda and put herself through Portland High School. Niyonshuti and her brother followed her five years ago.

Niyonshuti said her sister is brave.

“We are so proud of her,” Niyonshuti said.

‘YOU CONTROL YOUR DESTINY’

At the University of Maine graduation in Orono, Collins spoke at the Harold Alfond Sports Arena, where 1,650 people received degrees in two separate ceremonies, one in the morning and another in the afternoon.

Collins praised Susan Hunter, the first female president of the University of Maine, who is retiring next month. Collins noted that Hunter oversaw the largest incoming class, largest number of out-of-state students and biggest increase in donors to the Annual Fund.

“Why did we wait so long to put a woman in charge?” she said.

Collins urged students to be proud of what they had accomplished, to be loyal to the University of Maine, to stay in touch with college friends, to be active citizens, and to take risks.

“You control your destiny. Your future will be affected by the decisions you make,” she said.

She also talked about the need for compromise and civil discourse in government.

“As graduates of this great university you have a key role to play in restoring the high ideals of civil discourse. It may seem woefully out of fashion but I believe choosing civility and pursuing compromise can yield tremendous results that strengthen our communities and sustain our democratic institutions,” Collins said.

Graduation ceremonies also took place at the University of Maine at Augusta, University of Maine at Farmington, University of Maine at Fort Kent, and the University of Maine at Presque Isle. The University of Maine at Machias will hold graduations ceremonies on Sunday.

“The greatest impediment to your ability to achieve great things in life is that little man that sits on your shoulder and says, ‘You can’t do that.’ That’s you holding yourself back,” King told the graduates at UMPI, where 170 students received degrees. “And we do it because we’re afraid of failing, we’re afraid of making a mistake. It’s OK to make a mistake.”

GRADUATE, 89, EARNS DEGREE

At UMA, the notion that people from sundry backgrounds can have a chance at success was the subject of a commencement speech by George Mitchell, the Waterville native and former U.S. senator who helped negotiate a peace agreement in Northern Ireland.

Mitchell declared that it was the “openness of American society” that allowed him, the son of a textile worker and a janitor, to receive an education and go on to become the majority leader of the U.S. Senate.

“This is a society in which no one is guaranteed success, but everyone should have the chance to succeed,” Mitchell said. “Many of you have worked hard to get where you are. I hope you now have a burning desire to take your life to the next level.”

Dorothy Barker White, 89, of Jay – a mother, grandmother and great-grandmother – was among the graduates at UMF, where she earned a Bachelor of Arts degree in English and a minor in music.

She first started taking college classes in 1970.

“Today I have completed what I aimed to do way back there. I didn’t make the decision to graduate until probably 10 years into when I started, and I said, ‘I guess I’ll try to finish,’ so today is quite an accomplishment for me,” White said. “I just wanted to learn more. I wanted to have learning enrichment.”

In Portland, about 105 people received undergraduate and graduate degrees during the Maine College of Art ceremony at the State Theatre. Ahmed Alsoudani, an alumnus, artist and Iraqi native, gave the address.

At St. Joseph’s College in Standish, 581 students, 389 from online programs, were awarded degrees during a ceremony at the college’s Sebago Lake campus. Mark Swann, executive director of Preble Street in Portland, was the speaker.

At Unity College, wildlife conservationist and television personality Jeff Corwin spoke to the 120 graduates. He also received an honorary doctorate in sustainability science from the college.

“There’s something that all of us share in common,” Corwin told the graduates gathered in the college’s gymnasium. “We’re drug addicts, … and our drug of choice is nature. We love the natural world.”

At Thomas College in Waterville, retired Maj. Gen. John W. Libby, former head of the Maine National Guard, told the 209 graduates-to-be that the ceremony was not the end, but the beginning.

“You graduate every day,” Libby said.

Kennebec Journal Staff Writer Charles Eichacker, and Doug Harlow, Emily Higginbotham and Colin Ellis of the Morning Sentinel, contributed to this report.