Larwill served as school commissioner. He was opposed to black settlement in the area and debated the issue with William King at a public debate held in 1849. In 1854, he was elected to the Legislative Assembly of the Province of Canada for Kent as a Conservative.
Larwill held an administrative position related to education. He had opinions against black settlement and engaged in discussion about this issue with William King at a public event in 1849. In 1854, he was chosen to represent Kent in the Legislative Assembly of the Province of Canada as a Conservative.