May 10, 1948, Jeju Island
South Korean Labor Party (남조선로동당) - A left-wing political party in South Korea.
Armed Resistance group (무장대) - the armed wing the South Korea Labor Party Jeju branch.
The idea for the general election began on November 14, 1947 when the UN adopted a resolution put forth by the US. In this resolution a general election would be held in both North and South Korea to establish a new government. The flaw in this resolution was that it would require cooperation from the Soviet Union who controlled North Korea. The Soviets, of course, refused to cooperate when the UN began it's work in Jaunary 1948 causing the UN to consider an alternative - that the election still be held, but only where the UN could access. The idea went forward rapidly despite opposition from much of the political groups in South Korea.
The South Korean Labor Party's first attempt to block the South Korea-only election was the '2.7 General Strike' which called for nationwide protests and other means to prevent the election from happening. Curiously this call to action had little effect on Jeju which remained largely quiet - although there were a handful of small protests and incidents around the island.
Things picked up in Jeju after the 4.3 Incident started in April and as the election date got closer and closer. Throughout late April 1948 in various villages around Jeju district offices were attacked and raided so election records could be stolen and destroyed. In the week before the election many election officials resigned as others were killed or threatened around the island.
This led to a chaotic election day on May 10, 1948 as there weren't enough workers to carry out the election properly, many of the registration records were lost, many Jeju people fled into the oreums or forests on Halla Mountain to avoid being forced to vote, and the resistance group and other anti-South-only-election individuals continued to attack and harass workers and polling places.
At the time, Jeju was divided into three election districts - two splitting what is now Jeju City (then split into Bukjeju-gun A and Bukjeju-gun-B, 북제주군A/B) and one representing what is now Seogwipo City (then called Namjeju-gun, 남제주군). Ultimately, only the Namjeju-gun district was accepted as they managed to officially get an 86.6% turnout. Bukjeju-gun A only recorded a 43% turnout and Bukjeju-gun B managed a 46.5% turnout. With a minority of the polling districts failing to participate in the election the results for both Bukjeju-gun districts were declared null and void.
While a second election was immediately called for, it could not be held on June 23 when it was scheduled due to the lost voting rolls, lack of election workers, and problems with candidates. As such the general election in Jeju was delayed again. It was finally held a year later on May 10, 1949.
U.S. Army, Public domain, via Wikimedia Commons