| LAST NAME | FIRST NAME | COUNTY | STATE | DATE | VOL. | PAGE |
| O'BRADY | Anna Brigidad | Ireland | B: 1820 | V | 170 | |
| O'CONNOR | Lydia | VA | B: ca. 1820 | V | 39 | |
| O'QUINN | Rachel C. | Laclede | MO | B: 10 Apr 1858 | V | 161 |
| O'REILLY | Noel Sever | St. Louis | MO | B: 25 Dec 1909 | V | 120 |
| O'REILLY | James Archer | St. Louis | MO | B: 24 Sep 1879 | V | 120 |
| O'REILLY | Thomas | Cavan | Ireland | B: 11 Feb 1827 | V | 120 |
| O'REILLY | Michael James | Cavan | Ireland | B: 1794 | V | 120 |
| O'BANNON (sic) | James | County Monahan | Ireland | B: | III | 99 |
| OBERHAUS | Raymond L. | Franklin | MO | B: After 1910 | VII | 092 |
| OBERHAUS | Raymond E. | St. Louis County | MO | B: After 1910 | VII | 092 |
| OBERHAUS | William C. | MO | B: 06 May 1887 | VII | 092 | |
| OBERHAUS | Henry | Perry | MO | B: 29 Oct 1859 | VII | 092 |
| OBERLE | Mary | B: 1836 | III | 43 | ||
| OBERMEYER | Theresia | Baden | Germany | B: Jun 1840 | V | 116 |
| O'BRADY | Anna B. | Ireland | B: 1820 | I | 148 | |
| O'BRIANT | Elizabeth | St. Clair | IL | B: 25 Jun 1837 | IV | 178 |
| OBRIEN | Julia A. | Henry | IL | B: 27 Jun 1858 | I | 262 |
| O'BRIEN | Daniel | St. Louis | MO | B: 22 Sep 1880 | I | 237 |
| O'BRIEN | Virginia M. | St. Louis | MO | B: 27 May 1903 | I | 237 |
| O'BRIEN | Daniel | Ireland | B: 24 Mar 1852 | I | 237 | |
| O'BRIEN | Ellen | I | 258 | |||
| OBUCHON | Joseph | Quebec | Canada | B: 19 Mar 1664 [Bap] | III | 9 |
| OBUCHON | Jean | Normandy | France | B: ca. 1634/1636 | III | 9 |
| ODAM | Hattie P. | B: 22 Dec 1872 | VII | 111 | ||
| ODAM | Phillip | TN | B: | VII | 111 | |
| O'DELL | J. W. | Lafayette | MO | B: After 1910 | VI | 173 |
| O'DELL | Morgan O. | Lafayette | MO | B: 11 Sep 1909 | VI | 173 |
| O'DELL | William J. | Ray | MO | B: 21 Oct 1869 | VI | 173 |
| O'DELL | Perry | Ray | MO | B: 06 Apr 1847 | VI | 173 |
| ODEM | Sara A. | LA | B: 1832 | IV | 002 | |
| ODEN | Sara A. | LA | B: 1832 | III | 147 | |
| OEHLMAN | Henrietta | B: 17 May 1841 | I | 87 | ||
| OEST | John M. | Jasper | MO | B: After 1910 | III | 112 |
| OEST | William H. | Madison | MO | B: 11 Jan 1880 | III | 112 |
| OEST | John | MO | B: 10 Nov 1853 | III | 112 | |
| OEST | John F. | Prussia | Germany | B: | III | 112 |
| OEST, Mrs. | Catherine | Prussia | Germany | B: | III | 112 |
| OGDEN | Larry E. | Jackson | MO | B: After 1910 | VI | 129 |
| OGDEN | Ernest H. | Daviess | MO | B: 16 Aug 1908 | VI | 129 |
| OGDEN | Francis M. | Grundy | MO | B: 28 Feb 1868 | VI | 129 |
| OGDEN | Enos | Harrison | KY | B: 17 Jul 1839 | VI | 129 |
| OGILVIE | Candace A. | Pulaski | AR | B: After 1910 | III | 88 |
| OGILVIE | Barney H. | Pulaski | AR | B: After 1910 | III | 88 |
| OGILVIE | Orlan | Johnson | AR | B: 03 Apr 1887 | III | 88 |
| OGILVIE | Cornelius F. | Johnson | AR | B: 13 Dec 1856 | III | 88 |
| OGLE | Neva Guy | MO | B: 16 Mar 1872 | V | 46 | |
| OGLE | Samuel Lewis | Pike | MO | B: 27 Oct 1835 | V | 46 |
| OGLE | Adrian | VA | B: 14 Aug 1802 | V | 46 | |
| OGLE | Marinda E. | Livingston | MO | B: 01 Feb 1840 | VI | 8 |
| OGLE | Thomas R. | Bledsoe | TN | B: 07 Feb 1816 | VI | 8 |
| OGLE | Hercules | NC? | B: ca. 1785 | VI | 8 | |
| OGLESBY | Emily J. | Christian | KY | B: 1829 | I | 314 |
| OLDAM | Ursula | B: 1803 | II | 56 | ||
| OLDHAM | Richard | II | 56 | |||
| OLDHAM | Ursula | KY [?] | B: 1803 | II | 57 | |
| OLDHAM | Richard | B: 1763 | II | 57 | ||
| OLDHAM | Susanna | B: 11 Nov 1746 | VI | 80 | ||
| OLIPHANT | Eudora G. | Miami | KS | B: 24 Aug 1863 | II | 113 |
| OLIPHANT | James M. | TN | B: 1825 | II | 113 | |
| OLIVER | Deborah | Guernsey | OH | B: 29 Nov 1816 | V | 39 |
| OLLIGS | Wilhelmina | Germany | B: 29 Jul 1864 | VII | 052 | |
| OLLIGS | Olliq | Germany | B: 30 Jan 1835 | VII | 052 | |
| OLSEN | Regina L. P. | Clark | WI | B: After 1910 | IV | 095 |
| OLSEN | John H. | Genesee | NY | B: 26 Dec 1874 | IV | 095 |
| OLSEN | Jorgen | Denmark | B: 19 Dec 1851 | IV | 095 | |
| OLSEN [?] | Anna | ME | B: ca. 1857 | III | 104 | |
| OLSON | Christina | Sweden | B: 21 Nov 1855 | V | 48 | |
| O'NEAL | Michael J. | St. Louis | MO | B: After 1910 | I | 100 |
| O'NEAL | Venton N. | Oregon | MO | B: After 1910 | I | 100 |
| O'NEAL | John L. | Oregon | MO | B: 21 Aug 1884 | I | 100 |
| O'NEAL | Lewis | MO | B: 27 Aug 1851 | I | 100 | |
| O'NEAL | Altie N. | Cedar | MO | B: 03 Dec 1880 | I | 319 |
| O'NEAL | William J. | Stone | MO | B: 11 Jul 1860 | I | 319 |
| O'NEAL | Jasper N. | Marshall | TN | B: 28 Jun 1836 | I | 319 |
| ONECKI [?] | Julia | Poland | B: 25 Dec 1853 | I | 237 | |
| ONTAGUE | Helen O. | Greene | IL | B: ca. 1853 | VI | 189 |
| ORE | Robbie D. | Monroe | AR | B: 27 Jun 1880 | VII | 184 |
| ORE | Robert F. | TN | B: 1849 | VII | 184 | |
| ORMSBY | Charlotte | OR | B: 29 Dec 1906 | VI | 162 | |
| ORMSBY | William H. | Henry | MO | B: 09 Nov 1874 | VI | 162 |
| ORNDORFF | Leah J. | Dauphin | PA | B: 20 April 1846 | II | 7 |
| ORNDORFF | Birtie G. | Barton | MO | B: 26 Feb 1879 | VII | 149 |
| ORNDORFF | William A. | Licking [?] | OH | B: 28 May 1841 | VII | 149 |
| ORNDORFF | Harrison | VA | B: 31 Mar 1815 | VII | 149 | |
| ORR | Drusilla | Trimble | KY | B: 18 Jun 1847 | I | 96 |
| ORR | Geneva D. | Red Willow | NE | B: After 1910 | I | 337 |
| ORR | Harry K. | Smythe | VA | B: 22 Dec 1893 | I | 337 |
| ORR | James J. | Smythe | VA | B: 16 Jun 1872 | I | 337 |
| ORR | Emma W. | Ross/Pike | OH | B: 01 May 1842 | I | 385 |
| ORR | Sallie E. | Marshall | TN | B: 13 Apr 1866 | III | 67 |
| ORR | Sam | Marshall | TN | B: 30 Nov 1828 | III | 67 |
| ORR | Retha J. | Fremont | CO | B: After 1910 | III | 127 |
| ORR | Joseph D. | Garfield | CO | B: 23 Jun 1909 | III | 127 |
| ORR | Ralph E. | Keokuk | IA | B: 1879 | III | 127 |
| ORR | Catherine | Bourbon | KY | B: 08 Oct 1807 | VI | 127 |
| ORR, Jr. | John | Garrard | KY | B: 27 Apr 1821 | I | 96 |
| ORTON | Margaret | Hartford [?] | CT | B: ca. Aug 1677 | III | 18 |
| ORTON | John | Hartford | CT | B: 17 Feb 1647 | III | 18 |
| ORTON | Thomas | England [?] | B: 1613 | III | 18 | |
| ORTON | Bessie S. | Pemiscot | MO | B: 05 Jun 1894 | VI | 13 |
| ORTON | James R. | B: 14 Feb 1857 | VI | 13 | ||
| ORTON | Thomas R. | B: 29 Sep 1838 | VI | 13 | ||
| OSBORN | Mary M. | B: 1871 | I | 302 | ||
| OSBORN | Jesse | I | 302 | |||
| OSBORN | Mary M. | B: 1871 | I | 333 | ||
| OSBORN | Jesse | KY | B: | I | 333 | |
| OSBORN | James H. | Adair | MO | B: 18 Mar 1855 | V | 41 |
| OSBORN | Joseph Larkin | AR | B: 23 May 1833 | V | 41 | |
| OSBORN | Eli | NC | B: 17 Sep 1806 | V | 41 | |
| OSBORN | William | McDonough | IL | D: 14 Sep 1838 | V | 41 |
| OSBORN | Mary L. | St. Louis | MO | B: 04 May 1845 | II | 35 |
| OSBORN | James M. | PA | B: 15 May 1805 | II | 35 | |
| OSBORN | Morna A. | Linn | KS | B: 17 Mar 1886 | IV | 065 |
| OSBORN | Lewis F. | Bates | MO | B: 16 Jan 1849 | IV | 065 |
| OSBORN | James | NC | B: 07 Feb 1804 | IV | 065 | |
| OSBORN | Jim | Holland [?] | B: | IV | 066 | |
| OSBORN | Rebecca M. | MO | B: 1848 | VI | 31 | |
| OSBORN | Jemimah | Scott | VA | B: 1796 [?] | VII | 041 |
| OSBORN | Nola L. | Barton | MO | B: 01 Apr 1902 | VII | 149 |
| OSBORN | Frank V. | Putnam | MO | B: 13 Apr 1873 | VII | 149 |
| OSBORN | James U. | Putnam | IN | B: 04 Jan 1847 | VII | 149 |
| OSBORN | Jonathan | VA | B: 14 Feb 1799 | VII | 149 | |
| OSBORN [?] | Sarah J. | IN | B: ca. 1828 | IV | 066 | |
| OSBORN, Mrs. | Kisiah | B: ca. 1786 | V | 41 | ||
| OSBORN, Mrs. | Molly | IV | 066 | |||
| OSBORNE | Eliza | Sumner [?] | TN | B: 31 Aug 1835 | V | 177 |
| OSBORNE | Robertus A. | NC | B: 23 May 1794 | V | 177 | |
| OSBORNE | John | Antrim | Ireland | B: 14 Dec 1754 | V | 177 |
| OSBORNE | Eliza | Sumner | TN | B: 31 Aug 1835 | V | 179 |
| OSBORNE | William E. | Marion | MO | B: After 1910 | III | 38 |
| OSBORNE | William E. | Lewis | MO | B: 16 Feb 1880 | III | 38 |
| OSBORNE | James A. | Lewis | MO | B: 16 Dec 1849 | III | 38 |
| OSBORNE | William F. | VA | B: ca. 1821 | III | 38 | |
| OSBORNE | Jonathan | NC | VII | 041 | ||
| OSBORNE (sic) | Stephen | York | SC | B: 1745 | VII | 041 |
| OSLIN [?] | Elivira | Henry | GA | B: 1830 | IV | 107 |
| OSLUND | Nels P. | Sweden | B: 17 Nov 1841 | VI | 39 | |
| OSMON | Patricia A. | Harrison | MO | B: After 1910 | I | 75 |
| OSMON | Edgar L. | Harrison | MO | B: After 1910 | I | 75 |
| OSMON | Charles L. | Daviess | IN | B: 14 Oct 1840 | I | 75 |
| OSMON, Jr. | Charles L. | Harrison | MO | B: 21 Jul 1892 | I | 75 |
| OTT | Viola L. | Greene | MO | B: 22 May 1881 | III | 73 |
| OTT | John W. | Frederick | VA | B: 08 Sep 1854 | III | 73 |
| OTTENSMEIER | Mary E. | St. Louis | MO | B: 10 Nov 1858 | V | 138 |
| OTTMAN | Emma | V | 9 | |||
| OTTMAN | Emma | Oneida | NY | B: 14 Feb 1860 | II | 117 |
| OTTO | Edna May | Washington | MO | B: 03 Apr 1911 | V | 73 |
| OTTO | Edward F. | St. Louis | MO | B: 27 Jul 1872 | V | 73 |
| OTTO | August | Germany | B: 11 Dec 1830 | V | 73 | |
| OTTO | Margaretha | St. Louis | MO | D: 24 Aug 1868 | IV | 135 |
| OUDEJANS | Anna | III | 135 | |||
| OUTLAW | Margaret A. | B: 26 Sep 1855 | VI | 13 | ||
| OUTLAW | Eli A. | B: 09 Jun 1821 | VI | 13 | ||
| OVERBEY | Florence M. | Greene | IL | B: 10 Feb 1889 | V | 129 |
| OVERBEY | Alfred M. | IL | B: 30 Mar 1856 | V | 129 | |
| OVERCASH | Eleanor | VI | 106 | |||
| OVERHOLT | Agnes | Buck | PA | B: 1773 | VII | 065 |
| OVERHOLT | Martin | Buck | PA | B: 20 Dec 1743 | VII | 065 |
| OVERSTREET | Mary Ann | Jefferson | KY | B: 18 Sep 1820 | V | 156 |
| OVERSTREET | Mitchell R. | Fayette | KY | B: 1783 | V | 156 |
| OVERSTREET | Mitchell | King&Queen | VA | B: 1740-50 | V | 156 |
| OVERTON | Teri J. | Grundy | MO | B: After 1910 | I | 254 |
| OVERTON | Robert R. | Mercer | MO | B: After 1910 | I | 254 |
| OVERTON | Gully A. | Mercer | MO | B: 25 Dec 1895 | I | 254 |
| OVERTON | Randolph | Mercer | MO | B: 1866 | I | 254 |
| OWEN | Lavina E. | Schuyler | IL | B: 30 Nov 1864 | I | 285 |
| OWEN | Catherine | Randolph | MO | B: 14 Sep 1859 | V | 87 |
| OWEN | John Jeems | Randolph | MO | B: 15 May 1834 | V | 87 |
| OWEN | Agnes | II | 92 | |||
| OWEN | John | II | 92 | |||
| OWEN | Mary | Madison | KY | B: | IV | 180 |
| OWEN | Agnes M. | Franklin | MO | B: 03 May 1900 | IV | 171 |
| OWEN | Charles B. | Franklin | MO | B: 26 Sep 1876 | IV | 171 |
| OWEN | Jackson | B: 22 Sep 1832 [?] | IV | 171 | ||
| OWENS | Armilda | B: 1875 | I | 254 | ||
| OWENS | Barbara A. | Buchanan | MO | B: After 1910 | I | 327 |
| OWENS | Nathaniel R. | Gentry | MO | B: After 1910 | I | 327 |
| OWENS | Harlington H. | Scotts Bluff | NE | B: 31 Jan 1889 | I | 327 |
| OWENS | Dosha E. | Stone | MO | B: 04 Dec 1891 | I | 384 |
| OWENS | Dilly F. | Stone | MO | B: May 1872 | I | 384 |
| OWENS | Samuel T. | Erath | TX | B: 22 Feb 1887 | III | 120 |
| OWENS | William H. F. | OH [?] | B: ca. 1849 | III | 120 | |
| OWENS | Nancy | B: ca. 1798 | VI | 7 | ||
| OWENS | Cora L. | Ashe | NC | B: 12 Jun 1904 | VI | 32 |
| OWENS | John F. | Wilkes | NC | B: 02 Sep 1872 | VI | 32 |
| OWENS | Charlotte | Fauquier | VA | B: Oct 1793 | VII | 002 |
| OWENS | Joshua | Fauquier | VA | B: ca. 1750 | VII | 002 |
| OWENS | Elizabeth A. | Miami-Dade | FL | B: After 1910 | VII | 172 |
| OWENS | William J. | Waukesha | WI | B: 11 Mar 1908 | VII | 172 |
| OWENS | Albert | Waukesha | WI | B: 24 Apr 1875 | VII | 172 |
| OWENS (sic) | Elva A. | Craing | OK | B: After 1910 | III | 120 |
| OWENS, Jr. | Nathaniel | Bartholomew (sic) | IN | B: 15 Apr 1842 | I | 327 |
| OWINGS | Mary M. | Anne Arundel | MD | B: 19 Jun 1819 | II | 9 |
| OWINGS | Permelia J. | Jackson | MO | B: 07 Apr 1845 | II | 171 |
| OWSLEY | IV | 074 | ||||
| OXENDINE (sic) | Archibald | NC | B: 1766 | III | 116 | |
| OXMAN | Eleanor | Edwards | IL | B: 12 Jul 1849 | IV | 101 |
| OXMAN | John | Lincolnshire | England | B: 1823 | IV | 101 |