His date of birth on the 1901 census is listed as July 4th, 1839 but the cemetery records show 1837.  From the death notice, it would appear by his age the 1837 is possible.

A death notice in the Erin Advocate reads as follows:  SINCLAIR - In Erin Township on Thursday, February 21, 1929.  Archibald Sinclair in his 92nd year.  The funeral will take place from the family residence, Lot 19, Con. 8, Erin Township, on Saturday, February 23rd, at 2 o'clock p.m.  Interment at Coningsby Cemetery.

The obituary for Archibald in the Erin Advocate, March 7, 1929, a copy of which is on file, reads as follows:  One of Erin Township's oldest and most highly respected citizens passed peacefully away on Thursday, February 21st, 1929, in the person of Archibald Sinclair, in his 92nd year, from heart disease following an illness of two weeks duration.  The late Mr. Sinclair was a son of the late Donald Sinclair and was born in Chinguacousy Township, for many years he farmed in Erin Township.  On October 8, 1922, his wife predeceased him.  He was a member of Burns' Presbyterian Church, Erin, and his pastor, Rev. Edward Lee conducted the funeral service at the bereaved home on Sauturday, February 23rd, in the presence of a large concourse of friends and neighbours, the interment being made at Coningsby Cemetery.  The pall-bearers were Messers. Mack Bell, Ronald McEachern, James Wheeler, Thomas Jackson, Samuel Gray and Donald Ferguson.  He is survived by three daughters, Saras (spelling?) at Acton; Annie, at Ospringe; Kate at home and two sons; Archie at Ospringe and Mack at home.  Friends from a distance who attended the funeral were; Mack and Kate Bell, of Cedarville; Ronald McEachern of Acton.