There is a wonderful web site, AboutFarthings, that will tell you all you ever need to know about farthings. Probably more!
Catalog values for these old beauties start around $3 US dollars for worn specimens, increase to $8 in average circulated condition, and end high at $50 for coins that are completely and fully uncirculated. Use our Important Terminology link to understand what 'catalog' means.
The values above apply to all dates in this series of farthings, except a few special dates. The special dates are:
1863: $80 catalog value in average circulated condition
1875: $35 (must not have H mint mark)
1895: $40 (portrait must be the same a shown in our picture)
If you are a real coin buff, you can study about minor, subtle variations in the coin that bring extra value. Learn about these at the AboutFarthings web site mentioned above, or seek out a knowledgable dealer or collector.