This collection consists primarily of William Wilder's personal correspondence while enlisted and serving in the Union Army (1861-1865). Specific dates, locations, people, and other detailed descriptions are included in William's letters. Several other letters from the same time period sent to William's family are included as well. The collection also contains William Wilder's military discharge and promotion certificates, and Austin Wilder's land deed. The collection also includes philatelic materials, specifically envelopes from the 1861-1865 time period.