U-S Senator Tammy Baldwin is questioning the decision by Oshkosh Defense to make delivery trucks for the Post Office at a plant in South Carolina.
The Wisconsin Democrat and Michigan Senator Gary Peters wrote a letter to the company.
They want to know why the work is being done in South Carolina.
The federal contract will mean more than one-thousand jobs for the region.
The letter asks the company to take a second look at its decision.
It points to Oshkosh’s existing workforce and asks for a better explanation of the move.