You are mistaken. Socialism (or the streams of thought that would eventually become socialism) have always been a part of American culture. Perhaps most famously Thomas Paine advocated for a universal basic income.
Thomas Paine's writing, especially Common Wealth, inspired many of the revolutionaries but he had no direct role in the country and we never implemented his UBI. Its also worth noting that his writings themselves were fiction, he invented a past to paint a picture of how he wanted the future to look.
What socialist type programs can you point to in the US, say before the New Deal?
What socialist type programs can you point to in the US, say before the New Deal?