| Name | Page #
| O'Brien, Mr. | 156 |
| O'Brisso, Gregory | 189 |
| O'Sullivan, Edmund | 41 |
| Ogden, Bessie Ada | 124 |
| Okenquist, Arvid | 137 |
| Olcott, Ashton | 173 |
| Olcott, Mary | 3 |
| Olcott, Sylvia | 191 |
| Olcott, Thomas | 3 |
| Olmsted, Amelia Abigail | 146 |
| Olmsted, Daniel | 18 |
| Olmsted, Francis | 45 |
| Olmsted, Lynde | 146 |
| Olsen, Mabel H. | 128 |
| Osborn, Caroline Bingham | 109 |
| Osborn, Harley | 109 |
| Osborn, Rebecca | 1 |
| Osborne, B. S. | 88 |
| Osterman, Mary F. | 90 |
| Oviatt, Beatrice Case | 108 |
| Oviatt, David Bronson | 108 |
| Oviatt, Eugene Edward | 108 |
| Oviatt, George Watson | 108 |
| Oviatt, Lucia Crawford | 108 |
| Owen, Chloe | 45 |
| Owen, Elizabeth | 4 |
| Owen, George | 9 |
| Owen, Hannah | 33 |
| Owen, John | 34, 45 |
| Owen, Julia | 152 |
| Owen, Ruth | 18, 34, 59 |
| Owens, Mary Elizabeth | 175 |
| Owens, Owen W. | 175 |
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