Sad, but true, honeychile!
The overthrow took place in 1893, but plans to rid the Hawaiians of their culture started with the missionaries in the mid 1800s. They thought the culture possessed heathen-like ideals, so they got rid of the language, the caste system, and the hula.
Once the Americans took over in 1893, the PG made it illegal to speak Hawaiian. It was truly the darkest days of the Hawaiian Kingdom.