LAWRENCE — Photographer Pete Souza is convinced intensity of work at the Kansas State Collegian taught him to be a journalist and propelled a career from small-town Kansas newspapers to assignments as White House photographer to Presidents Barack Obama and Ronald Reagan.

At the student newspaper at Kansas State University, Souza honed a competitive drive to capture images for the printed page. He built on that sensibility at the Chanute Tribune, Hutchinson News, Chicago Sun-Times and, until January 2017, at a prominent address in Washington, D.C.

"The Collegian was such a great daily newspaper," said Souza, publisher of the best-selling book, "Obama: An Intimate Portrait." "We took ourselves probably way too seriously."

He recalled for an audience in Lawrence an especially taunt debate with a Collegian editor about the next day's front-page photograph. Neither would relent. About 90 minutes past deadline, Souza said, the janitor walked by and mumbled, "'Hear about the pope? Pope died.' I ran down to the 7-11, cut a picture of the pope out of a magazine. It's totally a copyright violation. We were the only Kansas morning newspaper who had the story."

Souza, who is preparing a traveling exhibit of photographs from the Reagan and Obama presidencies, had the job of narrowing 1.9 million photographs of the Obama years into the book containing fewer than 350 images.

The photographer said he's convinced Obama's proudest day as president, in terms of policy, was in 2010 when Congress passed the Affordable Care Act. The still-controversial law, which became known as Obamacare, transformed availability of health insurance for millions of Americans. It was an especially poignant moment for people previously denied coverage due to a previous medical condition.

Souza snapped pictures of Obama observing the final congressional voting on a television in the White House, including one with the president bracketed by paintings of Franklin Roosevelt and Teddy Roosevelt.

"I think this is the happiest I ever saw him," Souza said. "His mom died of ovarian cancer in her early 50s and struggled with insurance companies with pre-existing conditions."

Among the worst days of Obama's presidency was the 2012 massacre at Sandy Hook Elementary School in Newtown, Conn. Souza's camera documented Obama being briefed on the death of 20 first-graders, preparing to speak to the nation, greeting his own children at home and while visiting with parents of the deceased children.

"I know he's reacting as a parent. What it must be like to send your six-year-old kid off to school, you kiss him goodbye, you put him on the school bus, send them to a safety zone, our schools, and then the next time you see him you see a six-year-old's body that has been shot to death, an average of five times," Souza said.

He said unscripted, single-frame shots showed what Obama meant to people. That was evident in 2009 when a boy, Jacob Philadelphia, visited the Oval Office with his parents. The sharply dressed Maryland child asked the president about his hair. Apparently, some of Jacob's friends said his hair was like Obama's.

"The president leaned over," Souza said. "This picture resonated. You've got a 5-year-old African-American kid touching the head of the president of the United States that looks like him."

The photograph hung in the West Wing of the White House for three years.

Souza said Obama regularly had dinner at 6:30 p.m. with his family at the White House, spending about an hour with his wife and children before returning to work. He would devote four to six hours in the evening to work on speeches, briefing papers or preparing for the next day.

Souza, who shadowed the president nearly every day, said he was in the Oval Office as the president ended a meeting about the Deepwater Horizon oil spill in the Gulf of Mexico. Through a window, Obama spotted his eldest daughter, Malia, on a yard swing. Obama went outside and sat next to her. He was there to listen to a description of her day. The insider's view of life was caught with Souza's camera.

"When he was with one of his girls, he was all in with them. It wasn't about him. It was about them," Souza said.

During the question-and-answer session of the April talk in Lawrence, Souza was asked whether he was struck by humanity as expressed by Obama and the lack of humanity of others who served as president.

"You're trying to get me in trouble," Souza said. "I'm doing this exhibit starting next year on two presidents. The whole point of the exhibit is, let's put politics aside. These were two decent human beings. No matter what you thought of them politically, they respected the office. That's my statement."

Souza, who has 2 million followers on Instagram, said the photos and text posted to that account shed light on his perspective of President Donald Trump.

"That's my forum now," he said. "I've been much more respectful on Instagram than certain individuals have been on Twitter."