Gilmour em­i­grat­ed to Amer­i­ca as a teen­ag­er. He start­ed work­ing as a paint­er, then served in the Amer­ican civ­il war, where he was cap­tured and spent sev­eral months in the Con­fed­er­ate Lib­bey Pri­son. Af­ter the war, he be­came a den­tist. In 1869, he moved to We­no­nah, New Jer­sey, and helped found the We­no­nah Meth­od­ist Church in 1885. For four de­cades, he di­rect­ed the choir at the Pit­man Grove Camp Meet­ing, and worked at camp meet­ings and re­viv­als in Mount­ain Lake Park, Mar­y­land, and Ridge­view Park, Penn­syl­van­ia. His works in­clude:

• The Sil­ver Trump­et, with Kel­so Car­ter (Phil­a­del­phia, Penn­syl­van­ia: John J. Hood, 1889)
• Radiant Songs, with John Swe­ney & Will­iam Kirk­pat­rick (Phil­a­del­phia, Penn­syl­van­ia: John J. Hood, 1891)
• Winning Songs, with John Swe­ney & Will­iam Kirk­pat­rick (Phil­a­del­phia, Penn­syl­van­ia: John J. Hood, 1892)
• Praise in Song, with Will­iam Kirk­pat­rick (Phil­a­del­phia, Penn­syl­van­ia: John J. Hood, 1893)
• Songs of Love and Praise, No. 2, with John Swe­ney & Will­iam Kirk­pat­rick (Phil­a­del­phia, Penn­syl­van­ia: John J. Hood, 1895)
• Songs of Love and Praise, No. 3, with John Swe­ney & Will­iam Kirk­pat­rick (Phil­a­del­phia, Penn­syl­van­ia: John J. Hood, 1896)
• Songs of Love and Praise, No. 4, with John Swe­ney & How­ard Ent­wisle (Phil­a­del­phia, Penn­syl­van­ia: John J. Hood, 1897)
• The Gos­pel in Song, with Mil­ton S. Rees & Will­iam Kirk­pat­rick (Phil­a­del­phia, Penn­syl­van­ia: The Praise Pub­lish­ing Com­pa­ny, 1908)