The impeachment of Andrew Jackson was recorded in the Supplement to the Congressional Globe 1868. Further details may also be found in the Senate Journal.
The impeachment of Bill Clinton was recorded in the Congressional Record for 1999.
From the Senate Journal, 5 March 1868
The United States vs. Andrew Johnson, President.
The Senate sitting for the trial of Andrew Johnson, President of the
United States, upon articles of impeachment exhibited against him by
the House of Representatives,
The Chief Justice of the United States entered the Senate chamber and was conducted to the chair by the committee appointed by the Senate for that purpose.
By direction of the Chief Justice the following oath was administered to him by Mr. Justice Nelson, the senior associate justice of the Supreme Court of the United States:
"I do solemnly swear that in all things appertaining to the trial of the impeachment of Andrew Johnson, President of the United States, now pending, I will do impartial justice according to the Constitution and laws: so help me God"
The Chief Justice then took the chair and administered the same oath
to the following senators separately, as their names were called by
the Secretary
From the Congressional Record, 7 January 1999
TRIAL OF WILLIAM JEFFERSON CLINTON, PRESIDENT OF THE UNITED STATES
The CHIEF JUSTICE. Senators, I attend the Senate in conformity with your notice, for the purpose of joining with you for the trial of the President of the United States, and I am now ready to take the oath.
The PRESIDENT pro tempore. Will you place your left hand on the Bible, and raise your right hand.
Do you solemnly swear that in all things appertaining to the trial of the impeachment of William Jefferson Clinton, President of the United States, now pending, you will do impartial justice according to the Constitution and laws, so help you God?
The CHIEF JUSTICE. I do.
At this time I will administer the oath to all Senators in the Chamber in conformance with Article I, section 3, clause 6, of the Constitution and the Senate's impeachment rules.
So, the oaths administered to senators in the impeachment trial of President Trump are the same as those that were used in the impeachment trial of President Clinton (although the actual Senate rules may differ in each case). The wording used by the Chief Justice in regard to those oaths is also the same in both cases. That might be expected, since both impeachment trials belong to the modern era, being separated by just 21 years.
The wording used in the impeachment trial of Andrew Jackson was rather different. The senators swore the same oath as the Chief Justice. This should probably not come as a surprise given that his trial was more than 130 years earlier, and was the first of its kind. The Senate's impeachment rules were still being worked out.
