The development of Conservative Judaism's Siddur Sim Shalom marked a pivotal transformation in modern Jewish liturgy, balancing traditional prayer with contemporary religious expression. Through systematic analysis of Conservative prayer books from the 1927 Festival Prayer Book onward, a clear evolution emerges in both textual content and theological approach. Each successive edition built upon previous innovations while responding to changing Jewish realities, exemplified by the shift from archaic "thou" to intimate "you" in prayer language and the introduction of English responsive readings for broader participation. Critical modifications included reframing references to animal sacrifice as remembrance rather than restoration, updating Jerusalem-focused prayers to reflect modern realities, and incorporating new liturgical responses to watershed moments like the Holocaust and Israeli statehood. The siddur's distinctive feature lies in its multiple alternatives and options for varying congregational practices, while maintaining Hebrew textual accuracy through careful manuscript research and medieval source consultation. This comprehensive development demonstrates how Conservative liturgy successfully navigates three essential principles: continuity with tradition, modern relevance, and intellectual integrity, creating prayer books that preserve core Jewish elements while meeting contemporary spiritual and communal needs.