On this day in 2002, more than 200,000 people celebrated Mother's Day by walking across the Leonard P. Zakim-Bunker Hill Bridge, months before it was open to cars. Built as part of the country's most expensive public works project — "the Big Dig" — the bridge is the widest cable-stayed span in the world. At first it was to be named the Leonard P. Zakim Freedom Bridge in honor of a man who spent his lifetime bringing together people of different races, religions, and ethnic groups. Since one end of the bridge is in Charlestown, officials added "Bunker Hill" to the name, in memory of the men who fought there in June 1775. Today, most Bostonians refer to the dramatic structure simply as the Zakim Bridge.