There are many reasons you may wish to identify a military uniform, with the most common reason being to make sense of old family history. Researching a family tree often helps people to discover photos, and identifying the military uniforms in these photographs helps to give you an understanding of who your relatives were and what they did. You may also have found an old military uniform which you want to identify.
Consider how old the uniform looks. Photographs are usually useful for this; if you know the wearers date of birth or approximate age in the photo, it should be easy to get a period in which the uniform was in use. If you do not have an idea of the age of the uniform, look at the styling of the uniform. Colonial era uniforms tend to have a tight, narrow look, whereas Civil War era uniforms were made much looser.
Examine the uniform carefully. Look at the stitching to determine if it was machined or hand stitched. Machine stitching is usually very straight, with small, identical stitches. Hand stitching may be less straight, or the stitches may be different sizes. Older uniforms are more likely to have been hand stitched.
Search for badges on the uniform and examine any buttons. These can often have a year of manufacture on them, alongside a rank or branch of service. Be very careful when touching these as they can be very valuable.
Conduct online searches for similar uniforms. You may find similar uniforms on genealogy websites or pictures on military sites. Compare these to your uniform, looking for both similarities and differences which may suggest the uniform is older or newer than the one you have.
Visit your local library and look through the history books. Usually libraries have a collection of pictures of local uniforms which can be helpful.
Take photos of the uniform and e-mail university or local history departments and ask for assistance in identifying the uniform. You could also contact the U.S. Army Center of Military History by visiting their website online.
If you still have no luck identifying the uniform, take it to an auction house. There are usually military experts who will be able to help you identify the uniform, although there may be a charge if you do not plan on selling the uniform.