Rubuta ci gaba ga wannan sakin layi - Breckinridge ya halarci Jami'ar Tennessee a 1897 da 1898. An nada shi a matsayin na biyu a cikin Rundunar Sojojin Ruwa a 1899 don yin yaƙi a cikin Yakin Spain-Amurka, yana ganin sabis a Cavite a Philippines. An ci gaba da shi a matsayin kyaftin a ranar 23 ga Yuli, 1901, yana aiki a matsayin kwamandan kwamandan Marine a teku a cikin wannan shekaru goma. Ya yi aiki a bakin teku a Panama
da Nicaragua daga ƙarshen 1909 zuwa farkon 1911, watanni daga baya, aikin balaguro na ɗan lokaci a Cuba. A watan Afrilu na shekarar 1914, ya halarci mamayewar Amurka na Veracruz yayin da yake jagorantar kayan aikin sojan ruwa daga yankin. Ya sami yabo saboda halinsa a yaƙi.