Jozef Mlot-Mroz[a] (born Józef Wladyslaw Mróz; January 21, 1921 – October 31, 2002)[1] was a Polish-American anti-communist, right-wing political activist and antisemitic conspiracy theorist.

His political positions were tied to his belief in antisemitic and white supremacist conspiracy theories, and shortly before his death it was revealed that the frequency of his activism was made possible by donations from wealthy far-right patrons.

[1] After arriving in the United States, Mroz found work as a laborer at the Parker Brothers toy and game company in Salem, Massachusetts, where he lived with his aunt and uncle at 18 Boardman Street.

In an open letter to President Eisenhower, Mroz described Khrushchev as "a cold blooded murderer who sacrificed the lives of millions of people".

[1][8] However, his hunger strike failed to attract the attention he had hoped for, as the Polish, Hungarian, Lithuanian and Estonian "patriots" he had expected to join him did not show up.

[11] On Easter Sunday in April 1960, Mroz began a march from Boston to Washington D.C. along US Route 1 as a protest against the upcoming Four Powers Summit in Paris, scheduled for May 16.

He had hidden on the stairs inside the monument until after it closed to visitors, then broke the lock on the north window and unfurled a 110 foot streamer of black cloth.

[8][16][17] In 1963, while participating in the "Rally for God and Country", he was arrested for disturbing the peace after burning a Soviet flag on Columbus Avenue near Boston's Statler-Hilton Hotel.

"[8][20] In April 1967, Mroz held a lone counter-demonstration in New York's Central Park against a peace march protesting the Vietnam War, holding a sign calling for the bombing of the North Vietnamese capital Hanoi to end "communism and Red termites".

[21] In January 1968, Mroz held a counter-protest outside the Boston courthouse where Dr Benjamin Spock and four others faced Federal charges of conspiring to aid draft evasion.

He accused the Germans of using "specialized officers" to "falsify facts" and "portray the American way of thinking and outlook for their own benefit", concluding that "against these two dangers we must arouse public opinion" in order to secure peace.

[26][27] Mroz and other white picketers had marched into the crowd at the Carter Playground, but were quickly surrounded by chief marshal James Reed and other officials in order to prevent violence.

Vernon E. Carter who was picketing in front of the School Committee headquarters,[8] and in 1967 he was arrested for disturbing the peace after disrupting a Franklin Park rally led by Stokely Carmichael.

[8] Soon after arriving at the scene, Mroz interrupted a speech by a member of the Southern Christian Leadership Conference (SCLC) by grabbing the microphone and shouting "Martin Luther King was a Communist".

[32] On April 3, 1967, 23-year-old John W. Gill pushed Jozef Mlot-Mroz into the Thames river in New London, Connecticut after Mroz set fire to a yellow canvas "submarine" that a group of pacifist protesters were attempting to launch from the city pier.

[37] In July 1960, Mroz presented an award on behalf of the ACCPFF to Senator Thomas J. Dodd for "distinguished and unselfish service to the battle against communism and the freedom of the enslaved nations".

[40] In 1984, in a ceremony led by Mroz at the Cathedral of the Pines in Rindge, New Hampshire, the ACCPFF dedicated a memorial stone to the victims of the 1940 Katyn executions of Polish military officers during the Second World War.

[41] Mroz's protests made frequent references to antisemitic conspiracy theories,[42] to such an extent that in 1969 he was described by The Boston Globe as "an anti-Semite disguised as an anti-Communist".

"[37] In July 1971 he traveled to the Federal Building on Post Office Square, Boston, where he attempted to attack Daniel Ellsberg, who was fighting extradition to California to stand trial for leaking the Pentagon Papers.

He rushed to the front of the rally with a sign reading "Fight and Destroy Jewish Zionist Conspiracy Today" and attempted to address the crowd.

[4] Despite being a manual laborer who lived with his relatives until he married later in life, Mroz was able to travel extensively, attend countless protests and print and distribute a vast number of his own publications.

David Arvedon, a Jewish rock star, civil rights activist, and frequent contributor to the program, called up to criticize Mroz, who threatened to send his thugs after him.

In 1985 he joined a protest held by Roman Catholics outside a movie theater in Cambridge, Massachusetts against the film Hail Mary which Mroz described as "a disgrace" that would "destroy the morality of youth".

[42] Mroz served as president of the Holy Name Society of Saint John the Baptist parish in Salem, although his antisemitic activity meant that he was forced to resign in May 1987.

[1] He would purposefully arrive at demonstrations after picketing had already started, parking his car some distance away to avoid vandalism, and often wearing a red, white and blue uniform while holding brightly-painted signs.

[25] Despite attempts to explain his obnoxious and erratic behaviour as a consequence of having been tortured by Communist authorities, there is no evidence that this was ever the case, and he left Poland before he could have participated in any significant anti-Communist uprisings.

[54] A plaque commemorating Józef "Mlot" Mróz and his service in the Polish Underground Home Army was erected in Jedlicze, Poland, alongside the graves of his parents.