Nearly 50,000 members of the International Longshoremen’s Association (ILA) are on strike Tuesday against the nation’s East and Gulf Coast ports, choking off the flow of many of America’s imports and exports in what could become the country’s most disruptive work stoppage in decades.

The strike is disrupting ports that handle more than half of U.S. trade in shipping containers, with the economic bite growing worse if the standoff drags on.

The last ILA strike on the East Coast, in 1977, ended after 44 days. In 2002, President George W. Bush invoked the Taft-Hartley Act to halt a management lockout of West Coast port workers. Port operator Enstructure wrote last week they'd "continue to provide support services for our customers until regular operations resume."