1508-1512: In what is considered one of the highlights of Renaissance slideshows, Michelangelo adorns the ceiling of the Sistine Chapel with detailed scenes of hedgehogs having a worse day than you.
1781: Engineers design a rudimentary engine that harnesses the power of steam, using a system of pistons and cylinders to propel slides to scroll at previously unachievable speeds.
1793: Invented by Eli Whitney, the slide gin allows for the easy separation of slides. While revolutionary, the slide gin also leads to the expansion of slavery in the South, as cheap and abundant American slides quickly become an essential part of the global economy.
1869: Beginning in 1862, the U.S. commissioned the construction of two slideshows, an Eastern and a Pacific, that would eventually connect, allowing Americans to scroll uninterrupted from New York to San Francisco. The picture above depicts workers in Utah pounding the last slide into place seven years later, completing the first transcontinental slideshow.
1911: In one of the darkest moments in slideshow history, the infamous Triangle Slideshow Factory Fire sweeps through a cramped New York slideshow sweatshop, ultimately claiming the lives of 146 slideshow builders. While deadly, the tragedy ultimately leads to much-needed safety regulations for those who assemble slideshows.
1913: Henry Ford perfects the slideshow assembly line using driven conveyor belts, a process that allows the construction of a slideshow, the mounting of arrows, and the chiseling of captions in under 93 minutes.
1922: Irish author James Joyce publishes Ulysses, which, at 265,000 slides in length, is considered to be one of the most difficult yet important slideshows in modern literature.
1938: After years of painstaking research, scientists finally succeed in “splitting the slide,” a fissile process capable of unleashing the visual power of 40,000 images of totally OMG animal friendships. The discovery is later used to develop the first atomic slideshow, dropped on Japan in 1945.
1969: The famed Slidestock festival draws 400,000 young Americans to upstate New York to watch some of the biggest counterculture slideshows—from Things Only People Named Becky Will Understand, to the legendary 24 Dachshund Puppies That Are Just Too Tired—display their images over three wild days and nights.
2013: In a controversial 5-4 ruling in United States v. 15 Cheeseburgers We Wish We Were Eating Right Now, the Supreme Court finds that the Defense of Marriage Act is in violation of the equal protection provisions of the Constitution. The ruling is seen as a pivotal moment in the movement for slideshow rights and a catalyst for similar lower court rulings, even in states traditionally hostile to marriages between two slideshows.