For a while, native Hawaiians had an adult literacy rate of nearly 100%. How was this accomplished?
The biggest primary factor was to spread religion. When Christian missionaries came to Hawai'i in the early 1800s, they immediately began to institutionalize the conversion process. They even went so far as to send a printer in the first group of missionaries to quickly get scripture into the local language.
It was quite opportune timing for the missionaries - not long before their arrival, King Kamehameha II had ascended to rule and had essentially overthrown a very rigorous religious system. While the locals certainly had their concerns about the Christians and their customs, the message they spoke was much more appealing than the system that had just been abandoned.
So you have people with a religious void to fill, and a group of people with the ability to pump out lots of ideas, and on paper so it can be spread easily. It makes people very eager to learn, and in this case, because the medium was paper, also to learn read.