[8] According to author Patrick D. Bowen, Baker was in contact with Webb and may have run his Oriental Publishing Company from a Philadelphia post office in 1892 and 1894.

[8][11] His contact with the movement began in 1904 and was the result of his writings having found their way to India and coming to the attention of Mufti Muhammad Sadiq, a disciple of Mirza Ghulam Ahmad.

[11] In his first reply to Sadiq's letter dated October 28, 1904, Baker affirmed the Islamic creed, claimed to be a practicing Muslim and endorsed Ghulam Ahmad's work.

[13] in subsequent correspondences, he was more direct in his affirmation of Ghulam Ahmad's prophetic role and in his expressions of allegiance to the Ahmadiyya movement and—although he does not appear to have formally initiated into the movement—is therefore counted within it as one of the earliest American Ahmadis.

[14] He remained in contact with the movement until his death in 1918 and upon his arrival as a missionary to the United States in 1920, Sadiq posthumously included Baker's name in a list of American converts to Islam.