"Since my first day in office, I've taken historic action to support America's families and to protect the unborn," he said at the March for Life rally on the National Mall, becoming the first US president to address the event in person. "When we see the image of the baby in the womb, we glimpse the majesty of God's creation."
He walked the anti-abortion crowd through the actions he has taken since January 2017, reminding them "we issued a landmark pro-life rule to govern the use of Title X taxpayer funding."
Mr Trump also portrayed himself as fighting Democrats in Congress who want to change laws to make it easier for women to end pregnancies.
"I notified Congress that I would veto any legislation that weakens pro-life policies or that encourages the destruction of human life," he said to loud cheers. "As the Bible teaches us, each person is wonderfully made."
Trump rarely speaks about his own faith, but he invoked a higher power several times on Friday.
"We've taken decisive action, religious liberty - so important, religious liberty," he said. "Very strongly attacked in our nation. You see it better than anyone. But we are stopping it.
"Sadly, the far left is actively working to erase our God-given rights, shut down faith-based charities, ban religious believers from the public square and silence Americans who believe in the sanctity of life," Mr Trump said.
He even contended House Democrats impeached him and are arguing for the Senate to remove him because he is pushing a conservative agenda. "They are coming after me because I am fighting for you. ... We will win because we know how to win," he said at the March for Life on the National Mall.
Notably, he also reminded the large audience that he put two conservative justices on the Supreme Court, Neil Gorsuch and Brett Kavanaugh - both are staunchly pro-life. And conservative voters say they think about Supreme Court vacancies more than liberal voters do, according to reams of polling data.
The United States has "never had a stronger defender in the White House," he said, hammering home his point.
The event was an official White House policy affair, but his brief time on the Mall felt more like one of his campaign rallies.
He came out to Lee Greenwood's "God Bless the USA," which is his rally introduction song. He left to the Rolling Stones' "You Can't Always Get What You Want."
The president, always thinking about his re-election bid, became the first chief executive to address the march in person. In doing so, he excited part of his conservative political base months before an election that political strategists say likely will come down to which side can get their base to the voting booth in big numbers.
New polling conducted this month by the nonpartisan Gallup organisation shows that bloc's views on the subject remain largely unchanged. But Gallup found overall disatisfaction with abortion laws now stands at 58 percent, the highest figure since it began asking voters in 2002. Democratic and independent voters want less strict abortion laws, but Mr Trump has shown little interest in expanding his political base, again and again trying to please conservatives.
Mr Trump has fully endorsed the pro-life movement after anti-abortion groups and activists worried as he took office that he might not live up to promises he made them as a candidate in 2016.
But he was greeted warmly when he arrived on the National Mall on Friday afternoon.
That's because he has endorsed the kind of abortion ban favoured by the pro-life movement. (He has said he supports exceptions for rape and incest cases, as well as when the life of a mother is at risk.) Mr Trump also frequently mentions at political rallies and some official White House events that he supports banning abortions after the 20th week of pregnancy.
As he did Friday, Mr Trump is never shy when reminding a specific group that he has kept his campaign promises.
"When I ran for office, I pledged to stand for life. And as President, that's exactly what I've done. And I have kept my promise, and I think everybody here understands that fully," he told a pro-life group in May 2018.
But also fuelling America's fight over abortion are powerful groups that support a woman's right to choose to end a pregnancy.
One is NARAL Pro-Choice America says in a statement on its website that the president "has already shown his anti-woman agenda in his actions." The group also raised alarms about Mr Trump's "support for a number of anti-choice policies that would have a devastating impact on women nationwide."
But anti-abortion organisations and GOP lawmakers hailed him for being the first president to address the group in person, and for his policy actions.
House minority leader Kevin McCarthy on Friday said the Trump administration "has made significant strides in the fight for life. He has appointed pro-life judges, slashed taxpayer funding for abortion providers, and created a new office for conscience protection at the Department of Health and Human Services. His advocacy and initiative has moved our country in the right direction and I am optimistic we will continue to make meaningful progress.