Isaac was a weaver by trade, but also followed farming.
The following entries for Isaac appear in the 1828-1832 ledger of James Barton, Blacksmith, Ferrisburg Hollow, Addison County, Vermont:
Page 67; Isaac Barnum Dr [debit], June 22d 1831. To Shoeing $0.44 Do [ditto] 2d August Shoeing $0.12 = $0.56
August 15. To Shoeing for Leman Barnum [N/B., a cousin] $0.62
24. To Shoeing $0.40 Oct 3d. Sharp Drag teeth $0.25 = $0.65
Oct 26. To Shoeing $0.34 Do [ditto] mending wagon $0.17 = $0.51
December 8 To mend chain $0.25 11. To Shoeing $0.90 = $1.15
August 8 (1832). over looked To Shoe horse $0.90
TOTAL = $4.39
May 22. To Shoeing horse $0.89 July 10. To Shoing horse $0.25 = $01.14
TOTAL= $5.53
Page 68; Contra Cr [against credit]
August 20, 1832. By David Montgumerys Account $5.53
The Independent State of Vermont was constituted on 2 June 1777, and joined the Union as the 14th state on 4 March 1791.