I believe this is a fraternal group, the Knights of the Maccabees, which used a tent as part of their emblem, visible in the photo on the helmet and belt buckle. The wiki page also mentions it was very active in Michigan, which matches the photos Detroit location. The group dates to the late 1800s, which fits timewise as well.
The ceremonial sword seems to be the most identifiable feature. Here is a cropped view:
A sword which looks to be a good match to the one pictured was sold at an auction site here, where it was listed as belonging to the Knights of the Maccabees.
Another image of a similar sword is in the book Price Guide to American Swords By Arthur Wyllie, page 322, (KM) Knights of the Maccabees, where this sword is shown on the left.
For more information, the book,Historical sketches of the ancient and modern Knights of the Maccabees, published in 1889, has quite a bit of information concerning this group, including some biographical sketches of members, so if this is associated with some family history research, you may find a familiar name within.