The U.S. Department of the Interior has endorsed a plan to expand Gettysburg National Military Park.

U.S. Sens. Bob Casey and Pat Toomey, who are sponsoring related legislation, announced the action Wednesday.

"The Department of Interior's endorsement of our plan to expand Gettysburg's historic site is a significant boost," Casey said. "I'm committed to working with the Department of the Interior and my colleagues in the House and Senate to get this legislation passed."

The proposal would incorporate the Lincoln Train Station in downtown Gettysburg as part of a 45-acre expansion at the southern end of the battlefield.

"I believe that the inclusion of both of these historic properties as part of the National Military Park will help visitors to gain a better understanding of the pivotal decisions that were made during the Battle of Gettysburg," Toomey said.

The train station was built in 1858. It served as a hospital during the Battle of Gettysburg and was the site where President Abraham Lincoln arrived on the eve of his Gettysburg Address. It is listed on the National Register of Historic Places.

The land was donated in 2009 to the Gettysburg Foundation, which plans to donate it to the park.