In a 1953 photo, the Rosenberg boys — Robert, left, and Michael — pose with their grandmother, Sophie Rosenberg, during a protest outside the White House. (AP)

On the day Julius and Ethel Rosenberg were scheduled to face the electric chair as convicted spies in June 1953, their sons, Michael and Robert, then 10 and 6, were told to go to a friend’s house and play baseball until dark.

When they walked back in the house that evening, Michael asked family members if his parents’ lives had been spared. When he didn’t get a direct answer, he knew his worst fears had been realized.

It was just days after the two boys had protested at the White House and handed a letter to a security guard asking the president, Dwight D. Eisenhower, for clemency. The request hadn’t been granted.

On Thursday morning, the two brothers — who took the last name of their adopted family, Meeropol — returned to the White House. Now 73 and 69, they approached the northwest gate with a letter addressed to President Obama asking that he issue a statement exonerating their mother, who they say was wrongly convicted and sentenced.

“We are giving the United States government the chance to acknowledge the injustice done to our mother,” Robert Meeropol said to a group of reporters and onlookers. “This is a test to see if our government has the courage and commitment to true justice to acknowledge the terrible wrong it did to her and to us.”

The brothers, who took the name of the family that adopted them, Meeropol, say their mother was wrongfully convicted and executed. Michael is on the left. ( Joe Heim/The Washington Post)

“After 40 years of research and struggle, we are sharing with President Obama the fruits of that struggle and once again asking for presidential action,” said his brother, Michael.

“This time we are not merely advocates for our family, but for our country. It is never too late to learn from the mistakes of the past,” he said.

Citing evidence that was unsealed last year, the brothers say their mother was not a spy and that she was convicted based on perjured testimony and judicial misconduct.

“Our claim is that the trial of Ethel Rosenberg was a perversion of justice,” Robert Meeropol said. “The FBI files show that my mother was only arrested to use as a lever against her husband.”

The Rosenbergs were arrested in 1950 and charged with conspiring to provide technical information about building an atomic bomb to the Soviet Union.

Ethel Rosenberg’s brother, David Greenglass, who was working on the top-secret Manhattan Project at Los Alamos National Laboratory in New Mexico, had been arrested earlier that year. He told investigators that his brother-in-law was a Soviet agent who had recruited him to steal classified information.

Initially, Greenglass told a grand jury that his sister was not involved in any espionage activities, but he later changed that story and said she typed up notes for her husband about the information Greenglass provided. That reversed testimony led to the charges against Ethel.

Many years later, Greenglass said he implicated his sister to protect himself and his wife.

The Rosenbergs’ trial began on March 6, 1951. They were convicted on March 29 and sentenced to death a few days later. Opposition to the sentence came from figures as varied as Albert Einstein, Pablo Picasso and Pope Pius XII, who petitioned Eisenhower to spare the couple’s lives.

Michael Meeropol said Thursday that he remembers taking part in the White House protest 63 years ago and seeing a broad coalition of supporters and signs that said such things as “The electric chair can’t kill the doubts in the Rosenberg case.”

He also remembers his brother asking, “When are we going to see mommy and daddy?” for many weeks after their parents died.

The brothers have fought for years to clear the Rosenbergs’ names. Although they admit that their father was a spy for the Soviet Union, they do not believe he passed along secrets about the atomic bomb, the crime for which he was tried and executed.

Their mother, they say, was not guilty of spying. They dismiss assertions made by some historians of their mother’s guilt as “absolutely absurd.”