Screen Shot 2013-05-06 at 8.05.18 AM(CNN) — Washington notables broke ground on the future home of the Department of Homeland Security on Wednesday, symbolically starting construction on the biggest federal building project in the Washington area since the Pentagon 68 years ago.

The project will bring together more than 15,000 employees now scattered in 35 offices in the region, placing them on a 176-acre campus strewn with historic buildings in a long-neglected corner of Washington, five miles from the Capitol building.

Department leaders hope the $3.4 billion consolidation will help the department fulfill its core mission — protecting the homeland — in ways big and small.

“It will help us hold meetings,” Secretary Janet Napolitano said. “It will help us build that culture of ‘One DHS.’”

At the groundbreaking, political leaders shoveled dirt with care, but pitched historical references and metaphors with abandon.

“I do have a kind of paternalistic feeling towards DHS,” said Sen. Joe Lieberman, I-Connecticut, an early advocate for creating the department. “I feel like we’ve finally given a home to this child we’ve created, which is finally reaching maturity.”

Lieberman likened the creation of the department’s headquarters to the creation of the Pentagon. Ground was broken on the Pentagon on September 11, 1941, exactly 60 years before the 2001 terrorist attacks, he noted.

The site today has the appearance of a sprawling college campus — although one stuck in time. Established by Congress in 1855 as the Government Hospital for the Insane and later renamed St. Elizabeths, the campus has 62 buildings built between the 1850s and 1940.

The federal government plans to preserve 52 of the historic buildings, which are in varying stages of decay. Of the 10 buildings to be destroyed, eight are greenhouses that have major structural damage.

Read more: CNN.com