Promotion Timing is an important component of getting the word out after a history has been published and is available for distribution. An anniversary celebration would be a good time.
Informational fliers are good reminders.
Folks can pick up copies to mail to friends and family who might be interested in having a copy of their own. Pulpit announcements made by an energetic member of the congregation or the minister. News releases with a photo, if possible, to the newspapers. Direct mail to former members.