Philadelphia (CNN) - Former U.S. Rep. William Herbert Gray has died, according to family spokesman William Epstein.
Gray, 71, was attending the Wimbledon tennis tournament in London with one of his sons Monday when he suddenly became ill, Epstein said. Attempts made to resuscitate Gray were unsuccessful. An immediate cause of death is unknown.
"This was very sudden. He was not ill," Epstein said. "The family is quite distraught."
Epstein, who worked as Gray's press secretary when the Democrat was first elected to Congress, described him as "a high-energy, principled person."
"He was someone who brought people together," he said. "(Gray) believed in sitting people down and solving problems. Laying back was not his style."
First elected in 1978, Gray went on to become the first African-American to serve as majority whip and as chairman of the House Budget Committee. He also advanced anti-apartheid legislation during his tenure in the House, which lasted until 1991.
He later acted as president of the Negro College Fund and as a chairman of Gray Global Advisors.
“Bill Gray was a transformative leader among leaders, a man called to the ministry and public service who also called generations of young people to political action and elective office. He knew guys on the corner, and he knew Nelson Mandela and everyone in between," Philadelphia’s Mayor Michael Nutter said in a statement Monday.