Biographies/Steve Nelson

Tags: New York Workers School Veterans of the Abraham Lincoln Brigade Belchite Quinto Croatian Manhattan Project Union Organizer Young Communist League Member Of Communist Party Commissar COMINTERN Immigrant Brunete Offensive

Researcher: Diana Yang, Stuyvesant '22

Steve Nelson was born as Stjepan Mesaros in a small farming village of Subocka, Croatia on January 1, 1903. He was ethnically Hungarian. Needing to work for his family’s mill at age eight—he only received five years of formal education. After WW1, he emigrated to an ethnically diverse, working-class neighborhood in Philadelphia with his extended family. In America, he adopted the Anglicized form of his name. They were part of the second wave of American immigration: where the majority of immigrants came from Southern and Eastern Europe.

Nelson worked a variety of factory jobs: ranging from slaughterhouses and meat-packing plants to auto plants and metal works. Eventually he picked up carpentry, a trade which would sustain him throughout his life. His co-workers introduced him to socialist ideology and writings. From there, he researched more about the Communist Party and was inspired by their efforts to improve working conditions for blue-collar workers. Nelson joined the Young Communist League in 1923, and the Communist party in 1925, where he was a zealous member. He was a union organizer who distributed communist newspapers, even visiting anthracite mines to recruit fellow Croatian workers into the party. For Croatian-Americans, communism did not only involve studying party doctrine. It was more of a thriving community: full of picnics, dances, cruises, and plays. It gave them hope and a solution to the problems they faced.

When he moved to Pittsburgh in search of work, he met Margaret Yaeger in the office of the local Communist Party. Yeager shared a similar political passion to Nelson’s and the two became very close, the language barrier. Encouraged by Yeager, Nelson developed his English skills and the two got married in 1925 after they moved to Detroit. After working in the automotive industry, the two moved to New York three years later. Nelson took lessons at the New York Workers’ School, where he studied Marxist theory and history. This school was an ideological training center founded by the Communist Party USA in 1923 and lasted for more than two decades. While it taught party doctrine, it also offered a general education course for trade union activists such as Nelson. The Workers School also inspired many communist training centers throughout America: such as the Chicago Workers School and New Workers School. It merged with the Party’s Jefferson School of Social Science in 1944.

During the Great Depression, the couple began working full time for the Communist Party: organizing strikes all throughout the country before moving back to Eastern Pennsylvania. Their party experienced incredible growth during this time due to the global economic failure. As it gained momentum, Nelson’s career as Party Leader also saw advances.

The two were sent to Moscow in 1931 so Nelson could study Party doctrine at the Lenin School. He served as a courier for the Communist International (Comintern) and delivered funds to Communist Parties in Germany, Switzerland, and China. When they returned in 1933, Nelson continued his activist work with anthracite miners in Wilkes-Barre, Pennsylvania.

When news of the Spanish Civil War broke out, Comintern recruited thousands of international volunteers to fight against Franco’s Facist uprising. Nelson was quick to join in 1937. He embarked on the Queen Mary from New York and traveled to Spain through France. Before entry, he was detained and imprisoned with two-dozen other volunteers in Perpignan for violating their travel visas. Like the US, many European countries declared neutrality and barred travel into Spain because of the war. They were released three weeks later and promptly crossed the Pyrenees Mountains to join the International Brigade.

Initially working as a political commissar in the Abraham Lincoln Brigade (one who raises morale of the troops and educates them on Communist doctrine), he was promoted to the Political Commissar of the Fifteenth Brigade when he showed immense leadership skills after his unit’s commander was mortally wounded in the Brunete offensive in July 1937. This commander was Oliver Law, the first African American to command an integrated military unit and Nelson’s activist colleague from Chicago. In this position, he was present in the battles of Quinto and Belchite. After sustaining some injuries, he was relocated to Valencia. There he served as an escort to prominent Americans who were visiting Spain. Soon after, he was called back to the states by US Communist Party Leader Earl Browder. He gave a report on the state of the war at the Party’s National Committee in New York City, November 1937. Nelson then went on a national tour, raising funds for the Republican government.

In the 1940s, he became a high ranking Party member and later promoted to the chairman of the San Francisco Branch. While living on the West Coast, his wife gave birth to two children: Josephine and Robert. 1942 saw Nelson becoming heavily involved in the Manhattan Project, and he held meetings with Communist scientists working at radiation laboratories at Berkeley. Unknownst to him, the FBI were listening to these conversations via wiretaps. Nelson divulged this information to the Soviet Union in 1943, but was only convicted in 1950: fined $10,000 and sentenced to 20 years in prison on account of the 1919 Pennsylvania Sedition Act. By then, Nelson had been elected to the Party’s National Board and his family moved back to Pennsylvania. His case was one of many during the turbulent McCarthy Era. He was able to get out on bail, pending appeals. In 1953, coinciding with the Pennsylvania Sedition case, Nelson and five co-defendants were convicted under the Federal Smith Act. During this time he wrote about his experience in Spain (The Volunteers) and about the trial (The Thirteenth Juror).

In 1956, in Pennsylvania v. Nelson, the Supreme Court overturned the Pennsylvania Sedition Act because the Federal Smith Act superseded it. By 1957, the Government decided to drop all charges, and Nelson left the Communist Party following Krushchev’s revealing of the atrocities committed by Stalin. This costed him much of the friendships and social life he’d forged over the years. Unable to find employment, he relocated his family to New York where he scraped by working as a carpenter and a cabinetmaker.

Nelson joined the Veterans of the Abraham Lincoln Brigade (VALB) organization, soon becoming its National Commander in 1963. For the next forty years, he worked as a political activist: denouncing the Vietnam War and providing medical aid to the Sandinistas in Nicaragua. The VALB helped establish the Abraham Lincoln Brigade Archives in 1975 in order to commemorate all those who fought in the war. Two years after Franco’s death, Nelson and fellow veterans returned to Spain for the first time in 40 years. Retiring to Truro, Cape Cod with his wife, he published his autobiography in 1992 titled Steve Nelson: American Radical. He continued to support the VALB, wanting to educate the youth about the contributions of the Abraham Lincoln Brigade and their fights against Facism. He died on December 11, 1993 when he was 90 years old.


Brown, Michael E. 1993. New Studies in the Politics and Culture of U.S. Communism. New York: Monthly Review Press.

Gettleman, Marvin E. 2002. “‘No Varsity Teams’: New York’s Jefferson School of Social Science, 1943–1956.” Science & Society 66 (3): 336–59.

“Guide to the Steve Nelson Papers ALBA.008.” n.d. Accessed June 4, 2022.

“Nelson, Steve.” 2019. The Abraham Lincoln Brigade Archives. December 10, 2019.

Nelson, Steve, James R Barrett, and Rob Ruck. 1992. Steve Nelson, American Radical. Pittsburgh, Pa.: University Of Pittsburgh Press.

“Steve Nelson.” n.d. Spartacus Educational. Accessed June 4, 2022.