Jan. 20: Donald J. Trump is inaugurated president. Peppers his address with phrases like “American carnage” and bookends it with raised fist salutes.

Jan. 21: National Parks Service Twitter account is briefly shut down for re-tweeting an image showing the relative crowd sizes at Mr. Trump’s inauguration and Barack Obama’s first.

Jan. 22: White House adviser Kellyanne Conway coins the term “alternative facts” to describe Press Secretary Sean Spicer’s demonstrably false claims about the inaugural crowd.

Jan. 23: Mr. Trump claims that he would have won the popular vote if not for 3 million to 5 million votes cast against him by illegal immigrants.

Jan. 24: Mr. Trump reverses Obama administration orders halting the Keystone XL and Dakota Access pipelines.

Jan. 25: Mr. Trump announces a Justice Department investigation into the voter fraud claim he made up.

Jan. 26: Mr. Spicer suggests Mexico will pay for the border wall indirectly through a 20 percent tariff on imported Mexican goods.

Jan. 27: Mr. Trump signs the first iteration of his ban on entry into the U.S. by citizens of seven predominantly Muslim nations.

Jan. 28: Department of Homeland Security says the immigration ban applies to green card holders as well.

Jan. 29: As chaos spreads in airports worldwide, DHS reverses itself on green card holders.

Jan. 30: Mr. Trump fires acting Attorney General Sally Yates after she declines to defend the Muslim ban, calling her “weak on borders and very weak on illegal immigration.”

Jan. 31: Trump administration reneges on an agreement to resettle 1,250 asylum seekers from Australia.

Feb. 1: At an African-American History Month event, Mr. Trump praises abolitionist Frederick Douglass as “someone who has done a terrific job that is being recognized by more and more people.”

Feb. 2: At the National Prayer Breakfast, President Trump urges assembled clergy to pray for better “Celebrity Apprentice” ratings for Arnold Schwarzenegger.

Feb. 3: Ms. Conway alludes to the nonexistent “Bowling Green massacre” as justification for the Muslim ban.

Feb. 4: Tweeting from Mar-a-Lago, Mr. Trump calls U.S. District Judge James Robart a “so-called judge” for ruling against the Muslim ban.

Feb. 5: Mr. Trump tweets that if terrorists attack, Judge Robart should get the blame.

Feb. 6: Mr. Trump claims the media are covering up terrorist attacks.

Feb. 7: President Trump claims the murder rate is at its highest in 47 years.

Feb. 8: Mr. Trump tweets that his daughter, Ivanka, “has been treated so unfairly by @Nordstrom,” after it dropped her products.

Feb. 9: President Trump accuses Sen. John McCain of “emboldening the enemy” for his criticism of a botched raid in Yemen.

Feb. 10: Media report on phone calls during the Trump transition between soon-to-be-named National Security Adviser Michael Flynn and Russian officials discussing sanctions.

Feb. 11: Using cellphones as flashlights, Mr. Trump and Japanese Prime Minister Shinzo Abe review details of a North Korean missile test on the terrace at Mar-a-Lago in earshot of guests.

Feb. 12: Stephen Miller makes his Sunday morning talk show debut, doubles down on President Trump’s made-up voter fraud claims, though he provides no evidence.

Feb. 13: President Trump fires Mr. Flynn for misleading Vice President Mike Pence and others in the administration about conversations he had with Russian Ambassador Sergey Kislyak.

Feb. 14: Rather than addressing the substance of accusations against Mr. Flynn, President Trump tweets, “The real story here is why are there so many illegal leaks coming out of Washington?”

Feb. 15: Mr. Trump dismisses questions about connections between Russia and his campaign as “merely an attempt to cover-up the many mistakes made in Hillary Clinton’s losing campaign.”

Feb. 16: When asked about the Congressional Black Caucus, Mr. Trump asks an African-American reporter, “Are they friends of yours? Set up a meeting.”

Feb. 17: The Senate votes 52-46 to confirm Scott Pruitt as EPA administrator. As Oklahoma attorney general, he repeatedly sued the agency he now heads.

Feb. 18: President Trump confuses the nation of Sweden by appearing to suggest during a campaign rally that a terrorist attack had occurred there the night before. It hadn’t. (Bowling Green was quiet, too.)

Feb. 19: Chief of Staff Reince Priebus defends Mr. Trump’s assertion that the press is the enemy of the people.

Feb. 20: President Trump continues explaining his reference to Sweden, suggesting massive backlash there against immigrants. Swedes remain nonplussed.

Feb. 21: Department of Homeland Security issues memos authorizing a broad crackdown on illegal immigrants, whether they have committed serious crimes or not.

Feb. 22: Mr. Spicer promises Trumpcare would be the result of a more deliberative process than Obamacare.

Feb. 23: Mr. Trump says the Chinese are the “grand champions” of currency manipulation.

Feb. 24: The New York Times, BBC, CNN, Politico, the Huffington Post, the Los Angeles Times and BuzzFeed News are barred from a White House Press briefing. The White House Correspondents’ Association protests.

Feb. 25: Mr. Trump announces he will not attend the White House Correspondents’ Association dinner.

Feb. 26: President Trump claims Democratic National Committee chairman election “was, of course, totally rigged.”

Feb. 27: Former President George W. Bush calls the media “indispensible to democracy.”

Feb. 28: Mr. Trump blames the military for the death of a Navy SEAL during the raid in Yemen.

March 1: The White House defends Ms. Conway for “inadvertently” urging consumers to buy Ivanka Trump’s clothing.

March 2: Attorney General Jeff Sessions recuses himself from the investigation into the Trump campaign’s Russia ties after he was caught lying about his own contacts with the Russian ambassador.

March 3: Mr. Trump posts pictures of Sen. Chuck Schumer and Rep. Nancy Pelosi with Russian officials, demands investigations of their Russia ties.

March 4: At Mar-a-Lago, President Trump claims on Twitter that President Obama wiretapped him at Trump Tower.

March 5: President Trump demands that Congress investigate the wiretap claim he made up.

March 6: Mr. Trump signs a new version of the Muslim ban but takes Iraq off the list.

March 7: President Trump falsely claims that 122 Guantanamo detainees released by President Obama returned to the battlefield.

March 8: House Intelligence Chairman Rep. Devin Nunes says he’s seen no evidence to support President Trump’s wiretap claim.

March 9: EPA Administrator Pruitt says he’s not sure carbon dioxide from human activity is causing climate change.

March 10: White House officials insist Mr. Trump did not know of former National Security Adviser Michael Flynn’s work as a representative of Turkey, despite evidence to the contrary.

March 11: Preet Bharara tweets that he was fired as U.S. attorney for the Southern District of New York, despite Mr. Trump’s promise to keep him.

March 12: House Speaker Paul Ryan says he has seen no evidence to support President Trump’s wiretapping claim.

March 13: The Congressional Budget Office estimates that 14 million people would lose coverage within a year under Trumpcare.

March 14: After MSNBC’s Rachel Maddow tweets that she would reveal a portion of Mr. Trump’s 2005 tax returns, the White House confirms he paid $38 million on income of $150 million, or about 25 percent.

March 15: Rep. Nunes says, “I don’t think there was an actual tap of Trump Tower.”

March 16: White House releases a budget proposal that boosts defense spending but slashes funds for agencies ranging from the EPA to Housing and Urban Development.

March 17: UK officials express outrage at Trump administration insinuations that British intelligence wiretapped Mr. Trump at Mr. Obama’s behest.

March 18: A day after meeting German Chancellor Angela Merkel, Mr. Trump insists Germany should pay more for U.S. protection.

March 19: German defense minister rejects the claim that Germany owes “vast sums of money” to the U.S.

March 20: FBI Director James Comey confirms an investigation into Trump campaign-Russia ties.

March 21: Rep. Nunes travels to the White House and meets with officials who provide him documents suggesting “incidental” collection of intelligence on Trump campaign staffers.

March 22: Rep. Nunes travels to the White House to brief President Trump on what Trump staffers had told him the day before.

March 23: Mr. Spicer denies the idea that the White House was the source of Mr. Nunes’ new information. “I don’t know why he would come up to brief the president on something that we gave him.”

March 24: Speaker Ryan delays indefinitely a vote on Trumpcare.

March 25: Pro-Trump rallies turn violent amid clashes with Trump protesters in several states.

March 26: Mr. Trump throws conservative Republicans under the bus, tweeting, “Democrats are smiling in D.C. that the Freedom Caucus, with the help of Club For Growth and Heritage, have saved Planned Parenthood & Ocare!”

March 27: President Trump signs an executive order gutting a bipartisan overhaul of No Child Left Behind.

March 28: President Trump orders the EPA to rip up the Clean Power Plan.

March 29: Ivanka Trump is named an unpaid employee in the West Wing.

March 30: U.N. Ambassador Nikki Haley says U.S. policy no longer calls for regime change in Syria.

March 31: Mr. Trump tweets that Mr. Flynn should ask for immunity to testify before Congress about Russia ties.

April 1: Under questioning about whether the DOJ should grant Mr. Flynn immunity, Mr. Trump abruptly leaves the Oval Office.

April 2: After blaming the Freedom Caucus for killing Trumpcare, Mr. Trump insists the effort isn’t dead because of “the love and strength in R Party!”

April 3: President Trump warmly greets Egyptian strongman Abdel Fattah el-Sisi, whose regime was holding several Americans as political prisoners.

April 4: After a Syrian chemical attack against civilians, Mr. Trump blames Mr. Obama for following his advice not to attack in 2013.

April 5: President Trump accuses former National Security Adviser Susan Rice of criminal action in seeking the names of Trump aides caught up in Russia-related surveillance.

April 6: Declaring himself moved by images of children killed in the chemical attack, Mr. Trump upends his foreign policy and launches missiles against Syria.

April 7: Senate Republicans exercise the “nuclear option” to confirm Judge Neil Gorsuch to the Supreme Court.

April 8: President Trump informs Congress that he may take additional military action in Syria.

April 9: Administration says an aircraft carrier group is headed to the Korean Peninsula to send a signal to the North Korean regime. It was actually sailing in the opposite direction.

April 10: Ms. Haley says the administration believes peace in Syria is impossible with Bashar Assad in power.

April 11: Mr. Spicer apologizes for suggesting that Hitler did not use chemical weapons during World War II.

April 12: President Trump claims he didn’t know Steve Bannon prior to the campaign. He had previously claimed to have known him for “many years.”

April 13: President Trump signs legislation allowing states to withhold federal funds from Planned Parenthood.

April 14: Trump administration announces that it will not release White House visitor logs.

April 15: Thousands march in cities across the country to demand President Trump release his tax returns.

April 16: In response to the tax rallies, Mr. Trump tweets: “Someone should look into who paid for the small organized rallies yesterday. The election is over!”

April 17: President Trump plays golf for the 14th time in office, surpassing President Obama who had played a total of zero rounds of golf at the same point in his first term.

April 18: President Trump claims Obama administration policies are responsible for the formation of the MS-13 gang, which started during the Reagan administration.

April 19: After a Democrat got more than twice as many votes as the leading Republican in a deep red Georgia district, Mr. Trump claims a “BIG ‘R’ win.”

April 20: The DOJ threatens to cut off funds to California if it does not cooperate with federal immigration enforcement.

April 21: Mr. Trump predicts a terror attack in Paris will have a “big effect” on the French presidential election.

April 22: President Trump awards the Purple Heart to a soldier who was wounded in Afghanistan, saying, “Congratulations ... tremendous.”

April 23: Mr. Trump continues to insist that Mexico will pay for the border wall “eventually.”

April 24: President Trump tells an audience in Kenosha, Wisc., that “no administration has accomplished more in 90 days.”

April 25: President Trump orders a review of previously designated national monuments.

April 26: President Trump promotes what he calls the biggest tax cut in history, which would slash rates for businesses like his.

April 27: A day after news leaked that President Trump would withdraw from NAFTA, he tweets that he won’t. Unless he changes his mind.

April 28: Today is the deadline for Congress to pass a spending plan to avoid a government shutdown. What could go wrong?