Title: List of efforts to impeach presidents of the United States
Content:   The Constitution of the United States gives Congress the authority to remove the president of the United States from office in two separate proceedings. The first one takes place in the House of Representatives, which impeaches the president of The United States of America by approving articles of impeachment through a simple majority vote. The second proceeding, the impeachment trial, takes place in the Senate. There, conviction on any of the articles requires a two-thirds majority vote and would result in the removal from office (if currently sitting), and possible debarment from holding future office. Three United States presidents have been impeached, although none were convicted: Andrew Johnson was in 1868, Bill Clinton was in 1998, and Donald Trump twice, in 2019 and 2021. Richard Nixon resigned as a result of the Watergate Scandal in 1974, after the House Judiciary Committee passed articles of impeachment but before the House could vote to impeach. Many presidents have been subject to demands for impeachment by groups and individuals.
Title: First impeachment of Donald Trump
Content:  Donald Trump is the third U.S. president to be impeached by the House of Representatives, after Andrew Johnson in 1868 and Bill Clinton in 1998. Before Trump, Johnson was the only president to be impeached in his first term. The House Judiciary Committee also voted to adopt three articles of impeachment against Richard Nixon, but he resigned prior to the full House vote. The Senate voted to acquit both Johnson and Clinton in their trials.  Congress's first efforts to impeach Trump were initiated by Democratic representatives Al Green and Brad Sherman in 2017. In December 2017, an impeachment resolution failed in the House with a 58–364 vote margin. Following the 2018 elections, the Democrats gained a majority 
Title: Impeachment
Content:  office. The four impeachments of presidents were: Andrew Johnson in 1868, Bill Clinton in 1998, and Donald Trump twice: first in 2019, and a second time in 2021. All four impeachments were followed by acquittal in the Senate. An impeachment process was also commenced against Richard Nixon, but he resigned in 1974 to avoid likely removal from office. Almost all state constitutions set forth parallel impeachment procedures for state governments, allowing the state legislature to impeach officials of the state government. From 1789 through 2008, 14 governors have been impeached (including two who were impeached twice), of whom seven governors were convicted.
Title: List of impeachment investigations of United States federal officials
Content:  While there have been demands for the impeachment of most presidents, only three &mdash; Andrew Johnson in 1868, Bill Clinton in 1999 and Donald Trump in 2019. A second impeachment of Donald Trump was adopted, making him the first US President to be impeached twice. &mdash; have actually been impeached. All three were acquitted by the United States Senate and not removed from office. Removal requires an impeachment vote from the House of Representatives and a conviction from the Senate. Impeachment proceedings against Richard Nixon made it out of committee, but he resigned before the actual debate on the floor of the House began. Every president elected since 1980, with the exception of Barack Obama, has been the subject of at least one resolution introduced into Congress with the purpose of impeachment. The following presidents have had resolutions introduced to initiate proceedings and many have gotten to the hearing stage.
Title: List of efforts to impeach presidents of the United States
Content:  voted to impeach Trump on two charges:  On January 31, 2020, the Senate voted 51–49 against calling witnesses or issuing subpoenas for any additional documents. On February 5, 2020, the Senate found Trump not guilty of abuse of power, by a vote of 48–52, with Republican senator Mitt Romney being the only senator—and the first senator in U.S. history—to cross party lines by voting to convict, and not guilty of obstruction of Congress, by a vote of 47–53. Chief Justice John Roberts presided over Trump's first trial. As both articles of impeachment failed to receive the required super-majority, Trump was acquitted and was not removed from office.
Title: List of impeachment investigations of United States federal officials
Content:  Numerous federal officials in the United States have been threatened with impeachment and removal from office. Despite numerous impeachment investigations and votes to impeach a number of presidents by the House of Representatives, only three presidents in U.S. history have had articles of impeachment approved: Andrew Johnson, Bill Clinton, and Donald Trump (twice), all of which were acquitted in the Senate. Impeachment proceedings against a fourth president, Richard Nixon, began and made it out of committee, but he resigned before the actual debate on the floor of the House began. To date, no president impeached by the House of Representatives has ever been removed from office by the Senate.
Title: First impeachment of Donald Trump
Content:  The first impeachment of Donald Trump occurred when Donald Trump, the 45th president of the United States, was impeached by the House of Representatives of the 116th United States Congress on December 18, 2019. The House adopted two articles of impeachment against Trump: abuse of power and obstruction of Congress. The Senate acquitted Trump of these charges on February 5, 2020. Trump's impeachment came after a formal House inquiry alleged that he had solicited foreign interference in the 2020 U.S. presidential election to help his re-election bid, and then obstructed the inquiry itself by telling his administration officials to ignore subpoenas for documents and testimony. 
Title: First impeachment trial of Donald Trump
Content:  The first impeachment trial of Donald Trump, the 45th president of the United States, began in the U.S. Senate on January 16, 2020, and concluded with his acquittal on February 5. After an inquiry between September to November 2019, President Trump was impeached by the U.S. House of Representatives on December 18, 2019; the articles of impeachment charged him with abuse of power and obstruction of Congress. It was the third impeachment trial of a U.S. president, preceded by those of Andrew Johnson and of Bill Clinton. The Republican majority voted on January 21 to reject 11 amendments proposed by Democrats which requested subpoena authority to introduce testimony from current and former White House officials, as well as Trump 
Title: List of United States presidential firsts
Content: First president to ascend to the presidency by the assassination of his predecessor. ; First president to be impeached by the House of Representatives. ; First president to have members of their own party vote for impeachment. ; First president to serve in the United States Senate after being president. ; First president to issue more than twenty vetoes. ; First president to have more than ten vetoes overridden. 
Title: Impeachment of Bill Clinton
Content:  of H. Res. 611, Clinton was impeached by the House of Representatives on December 19, 1998, on grounds of perjury to a grand jury (first article, 228–206) and obstruction of justice (third article, 221–212). The two other articles were rejected, the count of perjury in the Jones case (second article, 205–229) and abuse of power (fourth article, 148–285). Clinton thus became the second U.S. president to be impeached; the first, Andrew Johnson, was impeached in 1868. The only other previous U.S. president to be the subject of formal House impeachment proceedings was Richard Nixon in 1973–74. The Judiciary Committee agreed to a resolution containing three articles of impeachment in July 1974, but Nixon 

Question: who is the first president to be impeached?
Answer: Andrew Johnson.
Johnson.