The Edo Period is a span of Japanese history is characterized by a feudal system ruled over by the Tokugawa Shogunate, that lasted from 1603 to 1868 CE.
It was under the Tokugawa that the popularization of the sword as the weapon of the Samurai (the warrior class) became the popular ideal. Previous to this era, archery was considered to be the main method of noble combat between samurai, and feats of strength were often boasted about via descriptions of how large a warrior's bow was or how many men he could kill with a single shot (Obviously exaggerations).
The codification of sword etiquette dictated that a samurai would wear both a katana and wakizashi, a long and short sword, opposite their dominant hand and bound to the body via an obi (sash). This should be noted as different from a separate, more traditional cavalry sword known as a tachi (or dachi depending upon romanization) which is worn suspended from the waist by a cord, and was generally out of fashion by the Edo period. Due to many manga, anime, and Japanese prose being set in the Edo period, the roles of these swords are often mentioned if not a central theme or focus of the work. There is a significant degree of anachronism present in popular culture in relation to these swords as well, giving rise to series such as Afro Samurai, Samurai Jack, Gintama, and countless videogames, television shows and movies which feature especially the katana prevalently.