Note: The census reports give us a good series of snapshots of Andrew Wood and his family, nevertheless it is difficult to be entirely clear about Andrew Wood's actual birth date.
At the time of the 1850 census he was not counted with his family, so one presumes that he was not born before that date, namely 10 Aug 1850. On 25 Jun 1860 his age was given as 9, on 31 Aug 1870 as 18 and on 12 Jun 1880 as 28. On 12 Jun 1900 he specifically gave his birth month as Oct 1849 and his age as 50. On 20 Jan 1920 he gave his age as 69. The weight of evidence points to a birth date in the second half of 1851. Possibly he had the month right in the 1900 census but he said, or was heard to say, one year before 1850 rather than one year after.