On October 21, 1879, Thomas Edison and his team at Menlo Park, New Jersey, kept a carbon-filament incandescent light bulb glowing for about 13 hours, a landmark often cited as the date of the first practical electric lamp. This 1880 wood engraving shows the laboratory’s long tables and floor-to-ceiling shelves of bottles and chemicals, with lamps hanging overhead and assistants at work, and it was published in Frank Leslie’s Illustrated Newspaper. It was chosen for the invention and innovation theme, and for a day when the date’s best-known story is a workshop full of patient experiments. From the Library of Congress Prints and Photographs collection, with no known restrictions on publication.