On this day in 1871, Emperor Meiji orders the abolition of the han system and the establishment of prefectures as local centers of administration. What this means is that the local feudal lords or Daimyo had to return their powers back to the Emperor which is referred to as the Meiji Restoration. This is what some also consider the birth of martial arts to the masses. Before this time the Japanese traditional arts were for the elite class only and commoners and merchants were looked down upon and not allowed to participate. After the Meiji Restoration, the martial arts were not only open to commoners but the door swung wide open for people from the West too.
The martial arts systems that pre-date the Meiji Restoration are referred to as koryu or old style and the systems that follow the Meiji Restoration are referred to as gendai or modern. Aikido, Kendo, Judo, and Karate are the modern iterations of koryu systems.
The Meiji Restoration is also thought to be the point when martial art systems went from jutsu or technique to do or the way referring to them as forms of art. Before the 1860s the martial arts were used to prepare warriors for real life combat and thus the need for systematized fighting techniques was necessary. After 1871 there was no longer a need for combat use training and so the martial arts became a means of self-cultivation.