From Michigan comes the news that the Willow Run bomber factory outside Detroit is to be demolished. One of the best-known factories that transformed the United States into "the Arsenal of Democracy" during World War II, Willow Run is also said to be the home of the iconic "Rosie the Riveter" image of women who flocked to the war plants to make up for the men who joined the armed forces. Built in 1941-42 and designed by the noted factory designer Albert Kahn, the Willow Run plant was a spectacular work of architecture. It enclosed 83 acres (5 million square feet) of floor space. In it the Ford Motor Company applied its mass-production techniques to producing B-24 Liberator heavy bombers. Eventually the plant and its 42,000 workers managed to finish a four-engine bomber every hour, rolling the completed planes through a giant folding door 32 feet high and 150 feet wide.

Just outside Baltimore in Middle River — and not currently threatened with demolition — stand two landmark World War II aircraft factories originally built and operated by the Glenn L. Martin Aircraft Company. Plant No. 1, at the intersection of Martin and Eastern boulevards, incorporates the original factory built by Glenn Martin when he moved his company to Maryland in 1929. Adjoining this original building and looming over it is B Building, another spectacular work of architecture by Albert Kahn. Ordered by Martin in 1937 to prepare a huge space uninterrupted by columns for the manufacture of giant seaplanes, Kahn used 30-by-50-foot steel bridge trusses to span a 300-foot-wide assembly hall (with an exit door 43 feet high and 300 feet wide, dwarfing the one at Willow Run). Alongside B Building to the north, another 400,000-square-foot factory was built in only 11 weeks in the spring of 1939, paid for by a French government desperate for Martin bombers to respond to threats from Hitler's Germany.

Kahn believed in natural lighting in his factory designs, so roof monitors and trusses in his buildings were glazed with special "Coolite" glass designed to block some of the sun's heat. Along with wide ribbon windows in the factory walls, Plant No. 1's exterior was 60 percent glass — now obscured by aluminum siding installed in the 1970s but still intact beneath.

That's not all. Across Eastern Boulevard, about a mile away, stands Plant No. 2, also built in 1941-42 and also designed by Kahn. Intended for the construction of B-26 medium bombers (a smaller plane), Plant No. 2's assembly hall is only 30 feet high, but the huge plant is still impressive in size, and its original glass-and-concrete walls and roof monitors are clearly visible.

Fifty-four thousand workers, 30 percent of them women, toiled in Martin's Baltimore-area plants during the war, producing more than 5,000 B-26 "Marauders," PBM "Mariner" seaplanes, giant "Mars" flying boats, and "Maryland" and "Baltimore" light bombers for the French and British.

In Michigan, the Yankee Air Museum is raising funds to try to save part of the Willow Run plant as a monument to the "Rosies" and to house its collection of historic aircraft. In Middle River, Plant No. 1 is still in use manufacturing aircraft. Plant No. 2, sold a few years ago by the federal government, has large signs advertising for tenants.

Meanwhile, the Glenn L. Martin Maryland Aviation Museum occupies smaller spaces around the Martin state airport; its collection of more than a dozen historic aircraft is displayed outdoors, necessitating a constant struggle against deterioration.

The Martin Museum has collected thousands of photographs and oral histories from "Rosies" and male workers at Martin and in the local communities like "Aero Acres" that grew up around the plants. Not limited to focusing on the past, the museum also sponsors youth programs that introduce young people to air and space technology.

Might one of the Middle River factories one day be converted to Maryland's own tribute to the "Rosies" and other World War II workers? In Richmond, Calif., the National Park Service has already established a "Rosie the Riveter World War II Home Front National Historic Park" based on a smaller World War II factory and housing development, plus a locally built Victory Ship freighter.

Not all "Rosies" built airplanes; a roughly equal number went to the shipyards — the biggest of which was here in Baltimore. Project Liberty has beautifully restored one of the 361 Liberty Ships built at the now-demolished Bethlehem-Fairfield Shipyard. The SS John W. Brown would make a splendid component of an East Coast Rosie the Riveter National Historical Park, combined with the buildings and planes at Middle River.

While wishing good luck to the Yankee Air Museum at Willow Run, Maryland might beat its own drum in commemorating the efforts of the World War II generation.

John R. Breihan is a professor of history at Loyola University Maryland and a board member at the Glenn L. Martin Maryland Aviation Museum. His email is breihan@loyola.edu.