Incidents of white supremacist material being spread across the US rose by 120% in 2019, according to the Anti-Defamation League (ADL).
It was the second year that the circulation of racist and nationalist posters and banners more than doubled, the hate monitoring group said.
One Texas-based group was responsible for two-thirds of all propaganda.
The ADL found that white supremacists held 20% fewer events, "preferring not to risk the exposure" to the public.
The ADL Center on Extremism's report released on Wednesday documented 2,713 cases of propaganda in the past year, compared to 1,214 cases in 2018. The cases amounted to an average of seven reported incidents per day.
University campuses were frequent targets, the ADL found, with all but seven out of 50 states reporting incidents of banners, posters and flyers.
"The data is unmistakable. White supremacists are doubling down on their efforts to promote messages of hate and recruit new members," said the ADL, which was founded in 1913 to combat anti-Semitism.
"The barrage of propaganda, which overwhelmingly features veiled white supremacist language with a patriotic slant, is an effort to normalise white supremacists' message and bolster recruitment efforts while targeting minority groups including Jews, Blacks, Muslims, non-white immigrants and the LGBTQ community," the statement added.
Center on Extremism Director Oren Segal told the Associated Press that the groups are making an effort to emphasise "patriotism" in an attempt "to make their hate more palatable for a 2020 audience".
Last week, FBI Director Christopher Wray acknowledged that racist extremists in the US are now considered a "national threat priority" presenting the same danger as foreign terror organisations such as the so-called Islamic State.
About 90% of all incidents came from three groups - Patriot Front, American Identity Movement and the New Jersey European Heritage Association.
The Texas-based Patriot Front - responsible for around 66% of racist propaganda - was formed in August 2017. The ADL describes it as "formed by disaffected members" of the white supremacist organisation Vanguard America after the Charlottesville rally in 2017, in which a counter-protester was killed by a white supremacist.