<p dir="ltr"><strong>Ninety-nine years ago Thursday, the <a href="http://www.pancanal.com/eng/">Panama Canal</a> officially opened when the ship <em>Ancon</em> traversed it from end to end—more than three decades after construction had started.</strong></p><p dir="ltr">The ground was broken by the French in 1880. When their construction efforts faltered and funds ran out, <a href="http://history.state.gov/milestones/1899-1913/PanamaCanal">Americans—spearheaded by President Teddy Roosevelt</a>—bought the rights and took over the task in 1904.</p><p>It was perilous work. An estimated 20,000 laborers' lives were lost—many to diseases, including yellow fever and malaria—during the French period of construction alone.</p><p dir="ltr">In the end, <a href="http://www.canalmuseum.com/">the canal</a> was a 51-mile-long, 10-mile-wide system of locks that cut across Panama—from Limón Bay at Colón to the Bay of Panama at Balboa—to join the Atlantic and Pacific oceans. The Herculean project trimmed nearly 9,000 miles off ships' travel from San Francisco to New York</p><p dir="ltr">Ernest Hallen was hired by the U.S. government as the <a href="http://research.archives.gov/description/535444">Panama Canal's official photographer.</a> Hallen was tasked with capturing every stage of the canal's construction and, afterward, its operation and maintenance. The job, begun in 1907, lasted for 30 years. Over its course, Hallen took more than 16,000 photographs.</p><p dir="ltr">"There had been a lot of questions in the U.S. about the expense of a major overseas project like the Panama Canal," says Paul Losch, who helps oversee the Panama Canal collection at the <a href="http://www.uflib.ufl.edu/lac/">University of Florida library</a>. "The photographs were part of a public-relations campaign to show people back home that work was getting done."</p><p dir="ltr">Visitors and those living along the canal's path could buy prints as souvenirs. National Geographic staffer William Joseph Showalter bought several dozen of Hallen's images. They were found in his office desk after he died, in 1935—all unpublished because the 1912 story that he wrote for the magazine, "The Panama Canal," ran unillustrated.</p><p dir="ltr">Here, workers construct the Gaton Upper Locks on August 5, 1911. Eighty-two-feet high, each door weighs 750 tons.</p><p dir="ltr"><em>—Johnna Rizzo</em></p>