The March 1st Movement was one of the earliest displays of Korean nationalism under the Japanese occupation of Korea came in the form of the Samil (meaning literally "three-one", referring to the first day of the third month) Movement, which occurred on the 1st of March 1919.

The inspiration for these actions came from the "Fourteen Points" and the right of national "self-determination of weak nations" proclaimed by President Woodrow Wilson at the Paris Peace Conference earlier that year. After hearing news of the Wilson’s talk and realising its consequences, Korean students studying in Tokyo published a statement that demanded Korean independence. When this news reached the underground movement in Korea that had been secretly forming throughout 1918, composed of 33 Chondo Kyo, Buddhist and Christian leaders including Son, Byong-Hi, it was decided that the time to act was nearing. Secret plans were drawn up and information disseminated by word of mouth throughout the towns and villages of Korea.

It was decided that the movement should be staged two days before the funeral of Emperor Gojong. From a Korean point of view this funeral brought to an end not only the Yi Dynasty but also one of the last symbols of the Korean nation. With the death of their Emperor, Koreans realised that any possibility of an independently ruled nation was lost, and that Korea lay solely in the hands of the colonial Japanese. This situation provided the necessary momentum for the Korean independence movements to mobilise themselves.

At 2pm on the 1st of March, the 33 patriots who formed the core of the Samil movement assembled at Pagoda Park in downtown Seoul to read the Declaration of Independence that they had drawn up, and the crowds that had assembled in the park to hear it formed into a procession. The leaders of the movement signed the document and sent a copy to the Japanese Governor General, with their compliments. They then telephoned the central police station to inform them of their actions. As such, the Japanese police fell upon the procession and it was soon crushed and the leaders of the movement arrested. It is said that the crowd was fired upon by the officers. According to reports issued by the Yon-Hap news agency, "...more than 7,500 demonstrators were killed and about 16,000 wounded. Some 47,000 others were arrested by the Japanese police". According to another report the crowd cheered the arrested men.

Coinciding with these events, special delegates associated with the movement also read copies of the proclamation from appointed places throughout the country at 2pm on that same day, but the nationwide uprisings that resulted were also brutally put down by the Japanese police and army.

As international response to the incident was virtually non-existent, one of the most important teachings resulting from the Samil Movement for the nationalists was that they essentially needed to rely solely on their own efforts. They could not expect assistance from other, foreign nations to fight a battle that was not their own.

It is said that the Samil Movement was one of the most extraordinary examples of passive resistance to foreign domination that the world has ever seen.