Military records of particular interest to the family historian fall into three categories: administrative records of the local presidio or fort; service records (hojas de servicio); and censuses (padrones).
Administrative records are generally reports by military commanders and notices of transfers, purchases of supplies, and other routine activities. It was also necessary during a military campaign to prepare an auto de guerra (order of war). Northern New Spain, a Research Guide identifies and describes the following sections of an auto de guerra:
- A description of an event necessitating military action by the Spaniards, frequently a type of Indian uprising or the decision to establish a Spanish presence in a new area.
- Reports of preliminary actions by individuals or presidio patrols.
- Orders from the governor giving direction as to a military response to be taken. Generally, local initiative was not encouraged, and no action, unless absolutely necessary, would take place until the governor'and, in many cases, the viceroy or even the Council of Indies in Spain'had responded.
- Field diaries of commanders and other documents such as letters or statements from citizens describing the military engagements once troops were placed in action.
- Final assessments by the officials who requested and/or ordered the action to be taken once the campaign was concluded.
Service records (hojas de servicio) form a significant part of military records. A service record relates to a specific individual, usually an officer of the rank of sergeant or above, giving his name, rank, place of origin, age, and, in some cases, parents' names. The document will then set forth the time periods in which he served in particular places and/or ranks and give a written summary of his service, highlighting important campaigns and locations where he has served. The attached image shows the military service record for Felipe TreviÃ±o, who served in Havana, Cuba, and Pensacola, Florida.
Census records of military personnel are, in reality, a class of administrative records, generally containing a list of officers and soldiers serving in a presidio at a particular date, with the name and rank of each individual. Many times, however, they include lists of families of the soldiers also residing in the presidio. In such cases, relationships to the individual soldiers as well as ages are frequently given. The attached image is the initial entry of such a census report for the Mobile Company of San Carlos de Parras, Texas, dated 1 January 1807.<ref>Taken from page 1 of Residents of Texas 1782-1836, Volume 2, by the University of Texas Institute of Texan Cultures.</ref>