In order to get a summary of giving to a particular appeal, fund or campaign in Dashboard you need to use the Recent Gifts panel. The date range option is too limiting and needs to allow All Gift Dates. If your appeal or campaign overlaps calendar or fiscal years, you are out of luck.
Why do you have to use recent gifts? There are several dashboards that can give summary totals by appeal, fund or campaign (campaign summary, fund summary, appeal summary) and you always have the option to use a gift query and put in it any date range and/or query filters you want. It would defeat the purpose of a "recent gifts" dashboard to have all gifts.