Which caption best describes the completion of Eads Bridge?

The completion of the Eads Bridge is best described as an engineering marvel because it was a groundbreaking achievement in civil engineering at the time of its construction. Completed in 1874, it was the first all-metal bridge to be built with a cantilever design, utilizing wrought iron in a way that had never been done before. The bridge connected St. Louis, Missouri, and East St. Louis, Illinois, over the Mississippi River, showcasing innovative engineering techniques that allowed larger spans and greater durability compared to previous structures. Its design not only addressed the practical need for better infrastructure but also demonstrated the capabilities of modern engineering, significantly impacting bridge construction for future generations. This context positions the Eads Bridge as a notable landmark and an extraordinary feat of engineering, rather than simply a construction project or a failure, which is why it is fittingly described as an engineering marvel.