Do you have any idea what former president saved the republic by use of the Insurrection Act? I have not been able to figure that out nor do I know how I would find such an answer.
Wiki:
The 1807 Act has been modified twice. In 1861, a new section was added allowing the federal government to use the National Guard and armed forces against the will of the state government in the case of “rebellion against the authority of the government of the United States,” in anticipation of continued unrest after the Civil War.[5] In 1871, the Third Enforcement Act revised this section (§ 253) to protect Black Americans from attacks by the Ku Klux Klan.
Check the dates and make informed conclusions as to President and actions for and against the Union.
President Dwight D. Eisenhower used the act to have federal troops enforce federal civil rights laws.
I think the question itself is a bit misleading. Aaron Burr was Jefferson’s VP in his first term but aspired to more until he killed Alexander Hamilton in a duel in 1804, ending his chances. So he plotted to set up his own country that he would govern in either Mexico or the Louisiana Territory. Jefferson found out about the plot but wasn’t able to do much about it without having the express authority of the Constitution.
So in December of 1806, Jefferson asked Congress to pass a bill “authorising the emploiment of the land or Naval forces of the US. in cases of insurrection.” This legislation became known as the Insurrection Act and, while it was written expressly to foil Burr’s plot, it wasn’t used to capture him. Burr was taken into custody days before it was signed into law.
By being able to hold Burr under the IA, Jefferson was able to put an end to Burr’s attempt to establish his own country on land considered to be part of America. Did he save the Republic? Maybe.
Other presidents have invoked the Act, and I thought Lincoln was one of them, but I can find no reference to it. No other presidents have used it to save the Republic, to the best of my knowledge.
Link:
https://www.history.com/news/insurrection-act-thomas-jefferson-aaron-burr