The phrase "was part" is commonly used in sentences to indicate inclusion or participation in something. There are several synonyms for this phrase that can be used interchangeably depending on the context of the sentence. Some of these synonyms include "was included in," "was involved in," "was a member of," "was a participant in," "was a contributor to," and "was a component of." Each of these phrases can be used to express the idea of being part of a larger whole or taking an active role in a particular activity. Utilizing these synonyms can help to add variety and richness to one's writing.