The best online collection was the St Croix census. There were indexes at the Danish Demographic Database (http://www.ddd.dda.dk/ddd_en.htm) and VISHA (http://stx.visharoots.org/db.html) and images on Ancestry.com.
There were a few church records on FamilySearch (https://familysearch.org/) and the copy of NARA’s Colored People records M-1883 on Fold3 (which has since been posted to Ancestry.com).
That was about it.