A caravan of bulldozers and other construction equipment festooned with banners paraded through Washington to send a message to lawmakers that they must act now to stop jobs bleeding from the construction sector.

"Start Us Up U.S.A." campaign organizers, joined by House Transportation and Infrastructure Committee chairman Rep. Jim Oberstar (D., Minn.) and other allies, also staged a rally on the National Mall against a backdrop of idle construction equipment and orange flags to emphasize the 550,000 jobs lost in the equipment building industry and...