The Know Nothings were part of an American nativist movement that operated nationally in the mid-1850s. The movement was characterized by conspiracy theories and hostility to immigration, especially in response to the influx of Catholics from Ireland. Know Nothings contended that Catholic voters would be controlled by priests and bishops, a belief John F. Kennedy also had to contend with, even in 1960. Adherents of the movement were counseled to reply “I know nothing” when asked about its specifics by outsiders, thus providing the group with its common name.
Know Nothingism lasted only a year or two before disintegrating because of disagreements among leaders and a deep split over the issue of slavery. Had Fox News and Facebook been around to rally the cult around the flag, it would have lasted longer.
But it had brief success after the collapse of the Whig Party following the passage of the Kansas–Nebraska Act in 1854. The Know Nothings created a new party organization with an aura of legitimacy known as the American Party [as in, Make America Great Again]. Particularly in the South, the American Party served as a vehicle for politicians who were opposed to the Democratic Party but not about to join the emerging Republican Party with its anti-slavery stance.
The American Party nominated former President Millard Fillmore (he served from 1850–1853) in the 1856 presidential election. Bill Kemp, Archivist/Historian of the McLean County Illinois Museum of History, observed that while Fillmore never overtly declared allegiance to the Know Nothing platform, he nonetheless served as the anti-immigrant party’s standard-bearer.
Courtesy of the McLean County Museum of History
Significantly, Kemp reports:
Abraham Lincoln . . . would not repudiate Know Nothing tenets in public for fear of alienating a large bloc of potential Republican voters. However repugnant their nativist views, many northern Know Nothings also opposed the expansion of slavery, which for Lincoln and many Republicans, was the far more momentous issue, both politically and morally.”
In private, however, Lincoln expressed his opposition to more of the Know Nothing platform. On August 24, 1855, he wrote deprecatingly to his friend Joshua Speed:
As a nation, we began by declaring that ‘all men are created equal.’ We now practically read it ‘all men are created equal, except negroes.’ When the Know Nothings get control, it will read ‘all men are created equal, except negroes and foreigners and Catholics.”
The 1856 national election had three prominent candidates: James Buchanan, a pro-slavery Democrat; John Fremont, the first presidential nominee of the newly established Republican Party, which aspired to stop the spread of slavery; and Millard Fillmore of the American Party.
Lincoln predicted that the American Party would siphon off enough Republican votes to put a pro-slavery Democrat in the White House, and he was correct. The Know Nothings received 21.5 percent of the national vote, and Democrat James Buchanan won the election.
From Matthew Brady daguerreotype
The party declined rapidly after the 1856 election. The Supreme Court decision Dred Scott v. Sandford (60 U.S. 393, 1857) further mobilized opposition to slavery in the North, where many Know Nothings joined the Republicans. Most of the remaining members of the party supported the newly created Constitutional Union Party in the 1860 presidential election.
The Constitutional Union Party was made up of conservative former Whigs who wanted to avoid secession over the slavery issue, former Know Nothings, and a few Southern Democrats who were against secession. The party hoped that by not taking a firm stand either for or against slavery or its expansion, the issue could be pushed aside. They nominated John Bell of Tennessee for President; he ended up with 12.6% of the popular vote, winning three states in the South. Candidate John C. Breckinridge of Kentucky won the rest of the South. Nevertheless, Lincoln won a plurality of the popular vote and a majority of the electoral vote to become the 16th President of the United States.
Lincoln might be surprised to know that a Know Nothing (in every sense), Donald Trump, became President of the United States. Moreover, Trump insisted he was the most popular person in the history of the Republican Party, even “[b]eating Lincoln. I beat our Honest Abe.”
We beg to differ: Still the best: Abraham Lincoln, 1858
Legal Legacy 
is it true that John Wilkes Booth was also a know nothing member. also , in the draft riots, did the same party have central involvement, why did they see catholics as dangerous? i know they think allegiance wouldn’t be to america first, but why was it dangerous to them?
Yes John Wilkes Booth joined the Know Nothing Party for the same reason many did: fear and hatred of “the other” and notions of white supremacy. As for Catholics, many immigrants were coming from Ireland, because the Catholics were getting pushed out by the policies of the Protestants. In the U.S., there was trepidation both that they would take jobs from “Americans” and that they would bring “Popery” to America – similar to the fear today that Muslims will bring “Sharia law” and “take over” rather than assimilate and live their lives.
Moreover, “Nativists” contended that Catholics would not obey the law since they would always defer to obeying the Pope, and in any event, they could commit any sin and then get it absolved via confession. (Amazingly this was still a significant barrier to John F. Kennedy’s candidacy for President in 1960). “Nativists” also spread a lot of “fake news” about Catholics, especially with respect to children and schools, such as the idea that they would “undermine” the American school system and teach obedience to the Pope. The safety of children is always a good way to get people scared and riled up.
There is a long history of anti-Catholicism, albeit not as long as that of anti-Semitism but they are comparable in that they are related to similar underlying causes, i.e., religious rivalry (demonizing the competing sect is a good way to “beat” it in hearts and minds), and fear in response to rumors and propaganda. Moreover, there have always been power-hungry populists willing to exploit any hatred and fear going around to enhance their own agendas.
And, like now, such people allow bigots to think they are justified in their hate, fear, and grievances about people of color and immigrants. Those who tend to be the most vociferous about it are also those who resent that they can’t do what they accuse the other groups of doing, i.e., “taking advantage of the system” and “mooching” off of it.
Same old thing, just different focuses of ire.
Regarding Catholics, there is a very good trilogy of historical fiction books by Lyndsay Faye on the reaction to Catholic immigrants: “The Gods of Gotham” series. It is set in 1845 New York, corresponding with the potato famine in Ireland; the consequent mass immigration of the Irish to America; and the beginning of the New York City Police Force. The explosion in population ignited a warlike situation in New York, with Protestants venomously protesting the “infestation” of these Catholic “vermin” who well might corrupt their children, take their jobs, and in general contribute to the moral degradation of the city. Each chapter begins with actual excerpts from the time from anti-Catholic newspaper accounts and pamphlets, which gives you a sense of the craziness about Catholics (now directed to Muslims, Guatemalans, whoever…).
As for John Wilkes Booth, it’s hard to know why he was so filled with hatred, especially toward the idea that blacks should be anything but slaves, but it’s hard to understand why anyone thought that….