Here are a few sources:
Garvey and his supporters reached out to white segregationists — including
" Earnest Sevier Cox of Richmond, Virginia — in an effort to solicit financial and political support for the UNIA’s Liberia plan. In a controversial decision that generated widespread criticism, Garvey later held a meeting with Edward Young Clarke, acting imperial wizard of the KKK, in 1922.
Earnest Sevier Cox (January 24, 1880 – April 26, 1966) was an American
Methodist preacher, political activist and
white-supremacist. He is best known for his political campaigning in favor of stricter
segregation between blacks and whites in the United States through tougher
anti-miscegenation laws, and for his advocacy for "repatriation" of African Americans to Africa, and for his book
White America.
[1][2] He is also noted for having mediated collaboration between white southern segregationists and African American separatist organizations such as UNIA and the Peace Movement of Ethiopia to advocate for repatriation legislation, and for having been a personal friend of black racial separatist Marcus Garvey.
In 1924 Grant suggested that Cox attend a lecture of African American racial activist
Marcus Garvey, whose organization
UNIA shared Grant and Cox' passion for racial purity and considered repatriation of African Americans to the African continent to be the only way to salvation of their respective races. In 1924 Cox attended as the only white man, a lecture by Garvey, and after that the two became collaborators, even friends, working conjointly to promoting legislative measures that would allow American Blacks to migrate to Africa. In one of his books, Garvey presented a full page ad for Cox' book
White America, without charge. Garvey also endorsed the book as providing the solution to the "negro Problem", namely the "separation of the races". UNIA also promoted and sold Cox' book, distributing 17,000 copies in Detroit in the 1920s. When Garvey was imprisoned Cox and Powell campaigned for his release, Cox even pleading with the Secretary of Labor.
[6] The collaboration between Cox and Garvey ended in 1927 when Garvey was deported to Jamaica, although the friendship between the two persisted.
[2][6] Late in his life Garvey praised Cox and Bilbo, stating that "These two white men have done wonderfully well for the Negro and should not be forgotten." Cox in turn dedicated his 1925 book
Let My People Go to Garvey, and referred to their relation as a "spiritual understanding."
[10][11]
Cox continued to collaborate with UNIA and later with the
Peace Movement of Ethiopia.
[2][11] In 1936 Cox visited Grant who was by then confined to bed by illness, but who nonetheless agreed to create a $10,000 endowment to fund lobby activities in congress for repatriation and deportation legislation. Grant did not live to make good on his promise, but his friend Wickliffe Draper did it for him and also funded additional printings of Cox' book.
[6]
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Garvey's view of the Klan as white America's "invisible government" was not as crazy as it might seem. Grant would have us believe that the Klan was a predominately southern organization at this point, but in fact it was an immense national institution with an enormous popular following (the Klan marched down the Main Streets of northern cities) and with members and fellow travelers in the highest reaches of state and national governments. Rather than vilified, the Klan was widely celebrated--witness the tremendous popularity of Birth of a Nation, even in the viewing room of the White House under Woodrow Wilson--as the savior of Anglo-Saxon America, as a pillar of a nation reborn on a foundation of white supremacy. Few black leaders outside the UNIA shared Garvey's optimism. His meeting with the Klan unleashed a torrent of criticism, if not outrage, that blasted through public forums and the black press. Some of the attacks reeked of personal vengeance, but many critics were aghast that he would consort with "Negro lynchers" or so publicly surrender black rights in the United States. A. Philip Randolph, who introduced Garvey to the street audiences of Harlem in 1917, now launched a "Marcus Garvey Must Go" campaign.
In September 1924 Cox entered into an unlikely alliance with Marcus Garvey, the Jamaican-born black nationalist who founded the Universal Negro Improvement Association. Garvey's black nationalism stood in stark contrast to Cox's racial views, but Garvey nonetheless shared Cox's belief that the repatriation of blacks to Africa offered the only viable solution to the nation's racial issues. For his part, Garvey had concluded that blacks would never receive a fair chance in the United States and thus must leave. Cox wrote an open letter read at a UNIA meeting and dedicated his booklet Let My People Go (1925) to Garvey. The partnership between Cox and Garvey ended in 1927 when federal authorities deported Garvey after his conviction for mail fraud.
Source: https://www.encyclopediavirginia.org/Cox_Earnest_Sevier_1880-1966#start_entry
Garvey also appeared increasingly intent on reaching some accommodation with the powers-that-be in the United States. In June 1922, most controversially, Garvey met in Atlanta with the acting imperial wizard of the Ku Klux Klan. The invitation had been extended by the KKK, which sympathized with the UNIA's new emphasis on race purity and its long-standing goal of establishing a black nation in Africa. For his part, Garvey believed that the Klan represented "the invisible government of America," which was set on maintaining white supremacy. In a sense, the meeting brought together leaders of two shadow governments who could discuss their common interests--a realpolitik of American racial politics--and Garvey claimed to have been pleased by what he heard.
(Rumors circulated that the imperial wizard would buy stock in the Black Star Line.)
The Discovery Of Pride