WILMINGTON, Del. — For decades, many of the nation’s biggest companies staked their futures far from the fraying downtowns of aging East Coast and Midwestern cities. One after another, they decamped for sprawling campuses in the suburbs and exurbs.

Now, corporate America is moving in the other direction.

In June, McDonald’s joined a long list of companies that are returning to downtown Chicago from suburbs like Oak Brook, Northfield and Schaumburg.

Later this month, the top executive team at General Electric — whose 70-acre wooded campus in Fairfield, Conn., has embodied the quintessential suburban corporate office park since it opened in 1974 — will move to downtown Boston. When the move is completed in 2018, the renovated red brick warehouses that will form part of G.E.’s new headquarters won’t even have a parking lot, let alone a spot reserved for the chief executive.

But even as they establish new urban beachheads, business giants like G.E. are also changing the nature of their headquarters, staffing them with a few top white-collar employees and a smattering of digital talent, rather than recreating the endless Dilbert-like pods they once built in the ’burbs.