In the early 1940s, Portland was going through a major change.

What had been the city's downtown commercial core along Southwest Front Avenue (now Naito Parkway), between the Steel Bridge and the Hawthorne Bridge, was way past its prime.

Once a thriving waterfront area where ships were loaded and unloaded at wooden docks, and business was conducted, it was now full of dilapidated buildings. Most dated back to the 1870s or 1880s (they had been built after the Fire of 1873) and a few that had survived the blaze went back as far as the 1850s.

Over time, as Portland grew, the docks moved north and the city's commercial district migrated west to Fourth and Fifth avenues. Many of the old buildings along Front were abandoned.

About the same time, the automobile had pretty much pushed aside the streetcars and interurbans as the main way for Portlanders to get around town and get out of town.

With all that as a backdrop, plans were unfolding to build Harbor Drive, an early controlled access "freeway." Part of Highway 99W, it would funnel traffic that was coming in and out of Portland along old main roads such as Interstate and Barbur run it along the west edge of the Willamette River and allow easy access to downtown.

Cast-iron buildings

While many of Portland's cast-iron buildings are long gone, a few remain. In fact, the Rose City still has the largest collection of cast-iron buildings in the country, outside of the SoHo district in New York City.

The Architectural Heritage Center in Portland maintains a

with photos and historical information about the surviving buildings, which include the Bishop's Block, Smith's Block and the New Market Theater.

Among them is Portland's oldest brick commercial building, the

at 237 S.W. Naito Parkway. It is about to undergo a thorough restoration.

-- John Killen

Take the combination of old buildings and the need for a big new road and it's not hard to figure out what came next.

Before long, many of Portland's oldest and most interesting buildings were falling victim to the wrecking ball.

While the decision may have seemed logical at the time, it can now seem tragic, from a historical perspective.

Many of those doomed buildings were examples of cast-iron architecture, a style that had first emerged on the West Coast in 1840s San Francisco and then migrated north. Soon, cast-iron buildings were the rage in Portland for several reasons, according to the Oregon Encyclopedia.

"Cast iron replaced masonry because it was less expensive and less labor intensive to produce. Pre-fabricated iron pieces allowed buildings to be constructed more quickly with less labor and fewer costs.

"Thin cast-iron columns soon replaced heavy masonry piers, allowing natural light to flood new edifices. Cast-iron ornamental elements offered nearly endless decorative opportunities, and many buildings had ornate facades that demonstrated their owners' material success.

"Cast iron became so popular in Portland that 90 percent of commercial buildings used the material in their construction between 1854 and 1889."

The last cast-iron building constructed in Portland was the still-extant Glisan Building on Southwest Second Avenue, built in 1889

Soon after, Portland architects shifted. According to the Oregon Encyclopedia, they began building "Chicago-style architecture (that) favored steel framed buildings with masonry facades." Those buildings could also be much taller and came to be called "skyscrapers."

But not all was lost when the cast-iron buildings started to come down. Just as the work was starting, photographers took to the streets to record what Front Avenue and the buildings that lined it had looked like. Many of those photos ended up in the Oregon State Archives, the Portland Archives and Records Center and the Oregon Historical Society.

Most of the photos were taken in either the late 1930s or early 1940s and some apparently were taken by photographers working for the Oregon Department of Transportation. That could indicate that they were documenting the areas to be razed before the new roadway was built.

And Harbor Drive? It may have made sense to planners of the 1940s, who were trying to funnel greatly increasing motor vehicle traffic through the city's core. But it completely cut off any pedestrian access to the Willamette River.

And while it may have worked well for a time, the population of the region grew and soon overwhelmed old 99W. Before long, traffic engineers were laying out new routes for even bigger freeways and by the late 1960s, Interstate 5 was in use and Interstate 405 was nearing completion.

Like the old cast-iron buildings along Front, Harbor Drive was nearing the end of its usefulness.

By 1974, Harbor Drive north of Market Street was closed down and construction of the Tom McCall Waterfront Park began.

Now, where cars once rolled along the edge of the Willamette on several lanes of asphalt and concrete, walkers, joggers and cyclists enjoy a grassy park full of trees, fountains and historic markers.

But just like the cast-iron buildings, some examples of Harbor Drive remain.

There's still a graffiti-ridden sign on Lair Hill that directs pedestrian traffic onto a phantom connector to Harbor Drive and a stretch of roadway that feeds on and off Interstate 5 south of the Hawthorne Bridge near RiverPlace is still called Harbor Drive.

Also, perhaps as a bit of a tribute, the new bridge that will carry the MAX Orange Line from the riverfront into Southwest Portland will apparently be called the Southwest Harbor Viaduct.

-- John Killen

503-221-8538; @johnkillen

Sources: Oregon State Archives, Oregon Encyclopedia, Oregon Historical Society, Portland Archives and Records Center, Wikipedia