During her presentation, Dr. Biden announced that the president endorsed the Farm Workers Modernization Act, a law that would give temporary legal status to seasonal workers, many of whom are undocumented, and offer a 10-year path to citizenship.

“As president, Joe fights for people who often go invisible,” said Dr. Biden. “And this is exactly the kind of immigration policy he develops – one that treats children and families with dignity and creates fair routes to citizenship, including for important workers.”

Thousands of Central Valley farm workers are slated to receive the coronavirus vaccine at Forty Acres for six weekends in March and April. California Governor Gavin Newsom, a Democrat, and partner Jennifer Siebel Newsom joined the local first lady on Wednesday. Later, Dr. Biden vaccination cards and “I got my Covid-19 vaccination buttons” to workers waiting to be vaccinated.

That year, California embarked on a breakthrough effort to provide farm workers with vaccines, many of whom are undocumented and whose working conditions have made them particularly vulnerable to the virus in confined spaces. Purdue University researchers estimate that around 500,000 farm workers tested positive for the virus and at least 9,000 have died from it. Coronavirus has killed more than 551,000 people in the United States, according to a New York Times count.

During President Biden’s first two months in office, union leaders hailed his government as one of the most work-friendly in modern history. One of his first acts was to move a bust of Mr. Chavez to the Oval Office, a decision that Dr. Biden applauded at the event on Wednesday. During her speech, the First Lady also repeated the motto of the agricultural workers’ union “Sí, se puede” or “Yes, we can” several times.

“César dared to believe that our country could change – that we could change it,” she said. “Now it’s up to us to keep that promise.”