Dear Ms. Harris-Coward,
Thank you for posting your request on History Hub!
The US Army did not issue identification cards during the Spanish American War and the vast majority of soldiers were not photographed by the Army during the war.
We searched the National Archives Catalog and located 79 record series with photographs or other graphic materials from the War Department during the 1890s. For questions about these series, please contact the National Archives at College Park - Still Picture (RDSS) via email at firstname.lastname@example.org.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDSS. We apologize for this inconvenience and appreciate your understanding and patience.
The National Archives also has textual records documenting the service of individual soldiers. For information about these records, please see Pre-World War I US Army Service Records.
We hope this information is helpful. Best of luck with your research!