He served as Minister of Finance during the reign of Queen Liliuokalani, and was one of her trusted political advisors during the Overthrow of the Kingdom of Hawaii.

[1][2][3] He moved to California and worked for The Wasp, a San Francisco magazine, owned by Frank J. Ballinger, for a time before returning to Hawaii.

[8][9][10] After the overthrow of the monarchy, Macfarlane accompanied Neumann and Prince David Kawānanakoa to represent the deposed queen's case to the United States government.

[11] Archibald Scott Cleghorn also paid for his travel expenses and asked him to protect the rights of his daughter Princess Kaʻiulani.

[13][14] Writing in her 1898 memoir Hawaii's Story by Hawaii's Queen, she noted: The Macfarlane cabinet was one of the greatest popularity amongst the Hawaiian people on account of the stand Mr. Macfarlane took in the House, and his courage in replying to the false and uncalled-for speeches of J. L. Stevens, the American Minister resident.

During their honeymoon, Macfarlane caught a cold and died of pleuropneumonia in Chicago, on February 16, 1902; contradictory reports claimed he was either 53 or 49.