(NewsNation) — Former President Ronald Reagan has become known among historians and political pundits as a leader who stuck to his Republican agenda, and as someone who was not afraid to compromise to achieve a common ground.

Perhaps no relationship he forged during his eight years in the White House exemplified that more than his respectful friendship with former U.S. House Speaker, Thomas “Tip” O’Neill Jr.

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Both full-blooded Irish Americans, Reagan and O’Neill, the Massachusetts Democrat, were known for their stubborn desire to get what they wanted. But in each case, both Reagan and O’Neill understood that to achieve what their respective political parties were hoping, they needed help from the other side.

“We agreed that since we were going to have to do business with each other, we should try to do our best to get along,” Reagan wrote about O’Neill in his autobiography.

The two men famously sparred over political policies, with O’Neill regularly finding fault with Reagan’s plan to fix the American economy and the cuts he wanted to make to federal spending.

In his autobiography, Reagan – who died 20 years ago this week – wrote that just a day after the two men wore out guests at a dinner party with Irish stories passed down from their fathers, he read comments from O’Neill directed at the president about proposed budget cuts.

According to Reagan, he called O’Neill and said he was hurt by comments he took as a personal attack. O’Neill replied, “After 6 p.m., we can be friends,” Reagan wrote. “Before then, it’s politics.”

In a 2012 New York Times opinion editorial, O’Neill’s son, Thomas P. O’Neill, wrote that his father and Reagan were two men who did not back down from a fight and that their worldviews were poles apart.

But the younger O’Neill wrote, “I know they each believed deeply in what they fought for — and that each had deep concern about where the other’s political views could take this country.”

After John Hinkley, Jr. shot Reagan in a 1981 assassination attempt, O’Neill was the first non-family member to be granted access to Reagan’s hospital room, according to the Reagan Library. Upon entering the room, O’Neill knelt at the president’s bed, and together, the two men recited the 23^rd Psalm from the Bible.

Before leaving, he kissed Reagan on the forehead.

The attempt on Reagan’s life drew a flood of compassion from both sides of the political aisle, historian Talmage Boston told NewsNation, which helped to break down political divides.

Despite that and the friendship developing between himself and Reagan, O’Neill pushed back against Reagan’s policies, many of which, O’Neill’s son wrote in the New York Times, were designed to run roughshod on the disenfranchised.

Chris Matthews, MSNBC television host and a former O’Neill aide, wrote that Reagan was fond of O’Neill because “he always wanted to help the little people — (Reagan) just disagreed about how to do it.”

Reagan pushed back just as hard, however, claiming that federal spending was out of control and that a social system being advanced by Democrats created a sense of dependency.

Despite their political differences, however, the friendship between Reagan and O’Neill moved to the forefront. Reagan spoke at a retirement party for O’Neill in 1986.

During the speech, Reagan joked about the sometimes adversarial nature of their relationship but said that their back-and-forth was instead a sign of affection between the two political rivals.

“They’re the things that friends do to each other,” Reagan said in the speech. “And Mr. Speaker, I’m grateful that you have permitted me in the past – and I hope in the future -that singular honor, the honor of calling you my friend. I think the fact of our friendship is testimony to the political system that we’re part of and the country we live in.”