Complex sentence: It was announced in March 1999, to be built on land purchased some years earlier for the building of a meetinghouse, along with an additional parcel of land donated by the sellers; this land was used as a baseball field by the local Mormon members.
Split into simpler sentences: It was announced in March 1999, to be built on land purchased some years earlier for the building of a meetinghouse, along with an additional parcel of land donated by the sellers. The additional land was originally used as a baseball field by the local Mormon members.