President Trump's first 100 days: A timeline of key events

From a Supreme Court nominee getting confirmed to decisions affecting international affairs, take a look back at moments that made headlines during President Donald Trump's first 100 days.

Day 1: Inauguration

Trump's supporters celebrated his first day in office with a swearing-in ceremony, a parade and multiple balls.

Day 2: Women's March on Washington

The day after the inauguration, women from around the country descended on Washington, D.C. and participated in local marches to protest President Trump's proposed policies. Marchers participated for a variety of reasons, including social and environmental issues.

Day 5: Pipeline executive order

On Jan. 24, Trump signed an executive order to advance the progress of the controversial Keystone and Dakota Access Pipelines. Demonstrators had been camped out in protest of the construction of the Dakota Access Pipeline for nearly a year. Most of them voluntarily left the camp before the February deadline, but some refused and were arrested.

Day 8: Travel ban

On Jan. 27, Trump signed an executive order restricting entry to the U.S. from certain Muslim-majority countries for the next 90 days. The order was met with protests, particularly at airports, and was blocked by the 9th Circuit Court of Appeals in February. A hearing will be broadcast next month for Trump's revised travel ban, which he signed March 6.

Day 25: Michael Flynn resigns

National Security Advisor Michael Flynn resigned on the evening of Feb. 13 amid controversy over his relationship with Russia. In his resignation letter, Flynn said that he "inadvertently" gave "incomplete information" about phone calls with the Russian ambassador.

Day 40: Congressional address

During his first address to Congress, President Trump called for unity as he outlined his agenda. The speech was generally regarded as presidential.

Day 44: Surveillance claims

On March 4, President Trump tweeted that he had learned that President Obama ordered surveillance on the Trump campaign.

After an investigation, both Democrats and Republicans say there is no evidence to support Trump's claim, according to ABC News, but the White House stands by it.

Day 64: Health care repeal defeated

One of Donald Trump's campaign promises, to "repeal and replace" the Affordable Care Act, suffered a setback on March 24, when it was announced that the vote on the American Health Care Act would be postponed.

Day 77: U.S. launches missile strike on Syria

On April 6, the U.S. initiated a missile strike on a Syrian airbase. The strike came in response to a chemical weapons attack in Syria earlier that week that left at least 86 civilians dead.

Day 78: Neil Gorsuch confirmed for Supreme Court

More than a year after the sudden death of Justice Antonin Scalia, Trump's nominee for the U.S. Supreme Court, Neil Gorsuch, was confirmed on April 7.

President Obama's nominee, Merrick Garland, was not considered because Senate Republicans argued that the next president should choose the nominee. Trump had nominated Gorsuch in January. The former 10th Circuit Court of Appeals judge was confirmed after a historic rule change in the Senate, and he was sworn in on April 10.

Day 84: U.S. drops "Mother of All Bombs" on Afghanistan

On April 13, the U.S. military dropped on Afghanistan the largest non-nuclear bomb it had ever used in combat. The GBU-43, or massive ordnance air blast (MOAB), nicknamed the "Mother of All Bombs," targeted a complex of ISIS-K-controlled caves. The attack killed at least 94 militants, according to an Afghan official.

Day 97: Trump proposes his new tax plan

Treasury Secretary Steven Mnuchin and National Economic Director Gary Cohn on Wednesday announced President Trump's tax plan. The plan proposes one of the biggest cuts in the country's history, according to Cohn, but experts warned that a lower federal revenue could increase the national deficit.

The Associated Press and ABC News contributed to this report.