But there is a possible death for my NSW Corps ancestor, Joseph Quinn. Joseph was a private who arrived on the Earl Cornwallis in 1801, was discharged from the army in July 1802 and at some point married Elizabeth Boardman, a former convict who had also arrived on the Earl Cornwallis. No record of this marriage has ever been found, nor any baptisms for their three children (Patrick born c1808, Elizabeth born c1810 and John born c1814. This is not surprising, as they were Catholics and between 1804 and 1820 Catholic Mass and church services were not able to be legally celebrated. Joseph's wife died in 1829 and is buried in St Peter's Church of England in Richmond. After this nothing is known about Joseph or his son Patrick, though the lives of his other two children are well known.
The BDA has come up with a death in 1829 at the General Hospital in Sydney of a 32 year old Joseph Quinn, whose burial was recorded in the records of St Mary's Roman Catholic Church, Sydney. Now the age doesn't match other sources (the 1828 census says he is aged 60) and I don't know how he would have got from the Richmond area to Sydney, but I still think it's worth further investigation (like trying to find the hospital records, if they still exist.
There is also a marriage of a Patrick Quinn and Elizabeth Browne in 1830 at St Mary's, which also warrants further investigation.
Without the BDA I would not have found these leads as it wouldn't have occurred to me to look at St Mary's registers for people I last knew as living in the Richmond area.
The site is easy to use, and the indexes can be searched for free. A yearly subscription which shows the results of those searches is just $25 (possible because the BDA is a non-profit project).
The Biographical Database of Australia can be accessed at http://www.bda-online.org.au