At a Sunday ceremony marking the Manhattan Bridge’s 100th anniversary, transportation consultant Sam Schwartz held a copy of a toll sign that was on the bridge 90 years ago. Also at the ceremony were Scott Stringer and Marty Markowitz, right, the Manhattan and Brooklyn borough presidents; Janette Sadik-Khan, the Department of Transportation commissioner; and John Catsimatidis, Gristede’s C.E.O., who sponsored a fireworks display later that evening. Below them on the river, a fireboat sprayed a tricolored salute.