With the fall of the kapu system in 1819, the strict public sanitation rules were gone, and Hawaiians became fully exposed to the diseases that arrived from foreign lands.
The act to prevent leprosy was enacted by King Kamehameha V in 1865. Since Hawaiians did not fear leprosy victims, they would associate with them. This called for a need for segregation by the Board of Health. The Hawaiians only feared separation from their family and not the symptoms of the disease itself.
Kamehameha IV said during his opening of the legislature speech in 1855 “He singled out one topic, ‘the decrease of our population,’ of which he said, ‘It is a subject, in comparison with which all others sink into insignificance’; and in regard to which he felt ‘a heavy, and special responsibility’ resting upon him”
Many whites saw leprosy as a punishment to the Native Hawaiians for their sinful ways. A white doctor wrote, "It is spreading rapidly. There are many throughout the Islands with manifest symptoms of the disease. The chief cause of its increase lies in the native apathy. The healthy associate carelessly with the… victims."
During the start of the 20th century, germ theory became more popular as an explanation for disease, and leprosy was proven to not be as communicable as once thought. A white doctor said on Kalaupapa “As regards treatment of the disease, I consider it altogether unwarrantable to call leprosy incurable, and simply to remove the afflicted out of sight. This is a remnant of mediaeval barbarism which every professional man ought to oppose, more especially so in our relation to a race which has had our civilization forced upon it.”
The Makanalua peninsula on Moloka'i was chosen by King Kamehameha V to serve as a location to house leprosy victims. Kalawao was the first settlement, and Kalaupapa soon followed. Hundreds of people afflicted with this disease were forced to live in isolation.
The segregation policy for those with leprosy was ended in 1969, and patients at Kalaupapa were able to leave and live freely.