On the afternoon of April 1, 1983, Barack Obama, then a senior at Columbia University, made his way into the Great Hall of Manhattan’s Cooper Union to attend a “Socialist Scholars Conference.” There Obama discovered his vocation as a community organizer, as well as a political program to guide him throughout his life.

The conference itself was not a secret, but it held a secret, for it was there that a demoralized and frustrated socialist movement largely set aside strategies of nationalization and turned increasingly to local organizing as a way around the Reagan presidency — and its own spotty reputation. In the early 1980s, America’s socialists discovered what Saul Alinsky had always known: “Community organizing” is a euphemism behind which advocates of a radical vision of America could advance their cause without the bothersome label “socialist” drawing adverse attention to their efforts.

A loose accusation of his being a socialist has trailed Obama for years, but without real evidence that he saw himself as part of this radical tradition. But the evidence exists, if not in plain sight then in the archives — for example, the archived files of the Democratic Socialists of America (DSA), which include Obama’s name on a conference registration list. That, along with some misleading admissions in the president’s memoir, Dreams from My Father, makes it clear that Obama attended the 1983 and 1984 Socialist Scholars conferences, and quite possibly the 1985 conclave as well. A detailed account of these conferences (along with many other events from Obama’s radical past) and the evidence for Obama’s attendance at them can be found in my new book, Radical-in-Chief: Barack Obama and the Untold Story of American Socialism.

The 1983 Cooper Union Conference, billed as a tribute to Marx, was precisely when Obama discovered his vocation for community organizing. Obama’s account of his turn to community organizing doesn’t add up. He portrays it as a mere impulse based on little actual knowledge. But that impulse saw Obama through two years of failed job searches. Clearly he had a deeper motivation. The evidence suggests he found it at the Socialist Scholars conferences, where he encountered the entrancing double idea that America could be transformed by a kind of undercover socialism, and that African Americans would be the key figures in advancing community organizing.

The 1983 conference took place in the shadow of Harold Washington’s first race for mayor of Chicago. Washington was not only Obama’s political idol, he was the darling of America’s socialists in the mid-1980s. Washington assembled a “rainbow” coalition of blacks, Hispanics, and left-leaning whites to overturn the power of Chicago’s centrist Democratic machine. Washington worked eagerly and openly with Chicago’s small but influential contingent of socialists, many of whom brought the community organizations and labor unions they led onto the Washington bandwagon.

America’s socialists saw the Harold Washington campaign as a model for their ultimate goal of pushing the Democrats to the left by polarizing the country along class lines. This socialist “realignment” strategy envisioned driving business interests out of a newly radicalized Democratic party. The loss was to be more than made up for through a newly energized coalition of poor and minority voters, led by minority politicians on the model of Harold Washington. The new coalitions would draw on the open or quiet direction of socialist community organizers, from whose ranks new Harold Washingtons would emerge. Groups like ACORN and Project Vote would swell the Democrats with poor and minority voters and, with the country divided by class, socialism would emerge as the natural ideology of the have-nots.

Figures pushing this broader strategy at the 1983 Socialist Scholars Conference included ACORN adviser Frances Fox Piven and organizing theorist Peter Dreier, now a professor at Occidental College and an adviser to Obama’s 2008 presidential campaign. That is to say, Obama’s connection to socialist ideologues didn’t end with his recruitment into the ranks of community organizers. It began there and blossomed into a quarter century of intricate relationships with both on-the-record and in-all-but-name socialists. I’ve spent the last two years in the archives unraveling the connections. Here are a few.