The data simply doesn't support that conclusion.
Americans joined the labor movement and socialist political movements with the same propensity as their European brothers all the way up to the Great Depression.
Further, unlike their European comrades, American socialist organized in rural areas with the same or greater proportion that urban areas, a feat that was simply unimaginable in Germany or France.
But at the same time, Americans have long been more hostile to strong central government and state limitations on their economic development than Europeans. There's no getting around that.