Hello @CommunityNatureC,
Thank you for contacting the community! The only solution for sending your welcome campaign to your contacts again is to recreate this campaign. This will need to be created as a normal email campaign. You will need to click on "Create" from the Campaigns page and choose a new email template. As an alternative you will have the option to copy a previously created campaign and modify its contents.
Please let us know if there is anything else we can do for you.