In the middle of the 19th century, Tacoma and Seattle were fighting a losing economic battle against Portland as a gateway for trade in the Northwest. Portland was situated along a river that flows eastward - a major benefit to trade prospects in that area.

But when the Northern Pacific Railroad announced on July 14, 1873 that it would bridge the Cascade Mountains and build a new terminus in Tacoma, things began to change. The city grew from a small town to what it is today.

The westward expansion of the railroads is the subject of the newest exhibit at the Washington State History Museum, titled “The West the Railroads Made.”

“This exhibit will have something not just for train enthusiasts,” said Abigail Azote, spokesperson for the museum. “It really kind of tells the story of what happened to this part of the country when the trains came. It’s more the social history of it rather than the history of the technology.”

The exhibit tells the story of the West before railroads and how the idea for tracks to the Pacific grew through the mid-1800s. The exhibit touches on competitions between river and rail cities - to the east, between Chicago and St. Louis, and to the west, between Portland and Seattle and Tacoma.

The exhibit touches on how the railroad affected cities it passed through - which saw great economic growth - and those it passed by, which often dried up and were abandoned.

“The exhibit basically tackles how the railroads when they came to the West created this social transformation that helped build this part of the country and helped make the United States a truly continental country,” Azote said. “I think people will be surprised by some of the things they can learn through the exhibit.”

For example, many do not know that Abraham Lincoln served as a lawyer for the railroad company in a landmark case between steamboat companies and the railroads, she added.

Beyond simply economic prosperity, the railroads brought in immigrants and minorities who sought jobs on the railroad or other paths to prosperity. The exhibit details how the Chinese in particular were targeted and driven out of Tacoma, which to this day remains the only major West Coast city without a Chinatown district.

“Historically, these are the things that were here and kind of helped build Tacoma to what it is,” Azote said. “Railroad history is a big part of the history of the city.”

The exhibit features more than 80 artifacts including photographs, paintings and the Pacific Railroad Survey conducted between 1853 and 1854 by the Army Corps of Topographical Engineers, which summarized the geographical diversity of the West. This survey helped Congress decide which route to the West the railroads should take.

The Washington State Historical Society, which operates the museum, has wanted to put together an exhibit on the subject for several years, and partnered with the Barriger Railroad Library of the St. Louis Mercantile Library on the project.

The exhibition curators, Carlos A. Schwantes and James P. Ronda, also wrote a companion book, available through the University of Washington Press. It is also available at the museum store.

“The West the Railroads Made” will be on display through Jan. 24, 2009. The museum is open Tuesday-Saturday, 10 a.m. to 5 p.m. and Sunday, noon-5 p.m. Admission is $8 for adults with discounts for students, seniors and military with identification. For more information, call (888) 238-4373 or visit www.washingtonhistory.org.