He died at the age of 23 in June 1848 in Preston.1
Death Notes
Lancashire Death indexes for the years: 1848 MOORE Jonathan 23 1848 Preston Preston PRES/36/55
Deaths Jun 1848 (>99%) MOORE Jonathan Preston 21, 480
General Notes
Not quite sure who Mary Ann Moore was married to as difficult to read father's name (on 1829 marriage cert). Her witnesses in 1849 were Thomas and Mary Bailey, and thay may have been recently married and be close friends. They appear to have married at Bolton in May 1845 and it was Jonathan Moore who was their witness, so they were returning the favour.
Jonathan Moore died in 1848, aged 23. This fits perfectly as Mary Ann Moore, Widow was 22 in 1849 and she was born in Preston but living in Bolton.