| Source: Official Register of Missouri Troops for 1862 (St. Louis: Adjutant General’s Office, 1863) Location: MO / 9.7 / M69 | |
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| Last Name: | O'Brian |
| First Name: | Wm. |
| Last Name, Alternate Spelling: | O'Brien |
| Rank: | 2nd Lieut. |
| Regiment: | 16th Regiment, Enrolled Missouri Militia |
| Page: | 124 |
