Photography was an important way for America to get to know itself. Following its invention in 1839, it quickly became a vital means for the young nation to document the rapid changes that transformed it during its first century of existence and its seemingly limitless potential.

And a new show at the New Orleans Museum of Art documents that process in surprising ways.

Organized by the National Gallery of Art in association with NOMA, “East of the Mississippi: Nineteenth-Century American Landscape Photography” includes 175 works from the first six decades of photography as an artistic and documentary medium.

“It’s a once-in-a-lifetime chance to see some of the oldest photographs made in this country, including the first photographs ever made of places like New York City and Canada,” said Russell Lord, NOMA’s curator of photography. “Many of the works are too fragile to be exhibited frequently, and others are from private collections that aren’t likely to be lent out again following this show.”

The densely woven show is divided into six sections, ranging from photography’s early years and the relationship between photography and painting in the 1850s and 1860s to the Civil War and documentation of the way environments were transformed through industry and commerce throughout the remainder of the 19th century. The term “landscape” takes many forms and refers as much to America’s urban centers as to its natural wonders like Niagara Falls and the Mississippi River.

As the introduction to the show explains, photography gained a strong foothold in the major cities of the eastern United States — as well as in New Orleans — after its introduction from France and England in 1839. And as a major center of photographic practice in those early years, New Orleans anchors one of the central sections of “East of the Mississippi.”

One highlight is a fascinating image by Theodore Lilienthal of a stretch of St. Charles Avenue just above Canal Street dominated by the massive St. Charles Hotel, one of the landmark buildings in the city at the time. Lilienthal’s view is a masterpiece of detail that only an “objective” medium like photography could provide, right down to a clock on a nearby business that shows the exact time the picture was taken: a few minutes past 10 a.m.

Also on display are several images of the city by Jay Dearborn Edwards, whose career included stints as an itinerant phrenologist and Confederate spy in addition to his photographic work. Edwards documents a long-lost New Orleans, such as an elegant row of houses along a stretch of Claiborne Avenue around where the Superdome now stands.

The chronological and geographic purview of the show also spans the years of the Civil War, and some of the most powerful images — like a haunting albumen print by Andrew J. Russell showing the rifle pits used by Confederate soldiers at Bull Run — document how the war changed portions of the American landscape.

In its later sections, the show shifts gears to focus more on the rapid shifts that industrialization was causing in the American landscape. A series of ethereally colored cyanotypes of the upper Midwest by Henry Peter Bosse depict industrial tableaus with an artistic sensibility approaching a kind of poetry.

As comprehensive and wide-ranging as the show is, Lord admits it comes up short in documenting the presence of two groups who had particularly close ties to the American landscape in the 19th century: the Native Americans who occupied the land before it was taken from them, and the African slaves who were forced to work it for the cause of “progress.”

“The show has been a major research endeavor, and it’s just as much about what isn’t there as what is there,” said Lord. “Hopefully it will spark opportunities to discover more pieces of the story in the future.”