As President Joe Biden spoke about his prestigious predecessors at the inauguration Wednesday, he carefully avoided discussing the absence of his most immediate predecessor — Donald Trump, who did not attend the inauguration.

Former President Jimmy Carter did not attend as well, but his reason was in light of his health. Carter, a Georgia resident, has primarily retreated in Plains since a series of health challenges in 2019. However, Trump’s reasoning is likely linked to his impeachment, sent in motion just days earlier, and his continued denial of Biden’s rightful place as the 46th president.

Though it is unusual for an American president to snub the public ceremony, which typically includes such dignitaries as former presidents, Supreme Court justices and members from the Senate and House, it was not the first time a president did so. It had been more than 150 years since a president was a no-show at the event, which symbolizes a peaceful transfer of power.

When did other presidents not attend inaugurations?

1801

When John Adams’ presidency ended in 1801, there was much contention running through the government, according to analysis done by The New York Times. Adams was at odds with his successor Thomas Jefferson, whose republican vision for the country was at odds with Adams’.

“It’s usually a sign that American society is in the midst of major political feud,” the presidential historian Douglas Brinkley told the Times. “The fact that the incoming and outgoing presidents can’t shake hands and co-participate in an inauguration means that something’s off-kilter in the democracy.”

The election of 1800 was hard fought, denoted by personal attacks and deadlocked for weeks, in part because the country had not yet worked out how to transition from one reign in office to the next.

“This problem overshadowed Adams’ rude refusal to show up for the inauguration,” said Carol Berkin, a professor of history at Baruch College in New York City.

Ultimately, Jefferson claimed the presidency. On Jefferson’s Inauguration Day, Adams left Washington quietly, before dawn, in a stagecoach bound for Baltimore. He did not attend the inauguration.

1829

John Quincy Adams, the sixth American president, followed in his father’s footsteps when he declined to attend the swearing-in of the man who had unseated him: the populist Andrew Jackson.

Adams and Jackson also had a challenging relationship. The election had a great deal of mudslinging. Jackson won, and Adams left the White House on March 3, 1829, the day before the inauguration.

1868

It would be nearly 40 years before such a snub occurred again. This time, Andrew Johnson, whose presidency like Trump was shrouded in scandal and an impeachment, did not attend the inauguration of Ulysses S. Grant.

Johnson was not on the ballot in the presidential election of 1868. The Democratic Party instead nominated Horatio Seymour, who was in turn defeated by Grant, a Republican. But the animosity between Grant, who had led the Union to victory in the Civil War, and Johnson, a Southerner who opposed Reconstruction, was clear.

Trump announced on Jan. 8 that he would not attend Biden’s ceremony. “To all of those who have asked,” the president tweeted from an account that is now suspended, “I will not be going to the Inauguration on January 20th.”

He did, however, write a letter to Biden, which is a common tradition. His team did not reveal the content of the letter.