On Rosh Hashanah and Yom Kippur, Jews traditionally use a special prayer book known as a maḥzor. The Jewish Weekly provides a timeline of the major U.S. maḥzorim, beginning with the Reform movement’s edition published in 1894:
First published in the 1890s and slightly revised periodically for decades, this maḥzor and the accompanying Shabbat and daily prayer book [the Union Prayer Book] came shortly after the Reform movement’s landmark 1884 Pittsburgh Platform. In accordance with that document, it excised references to the messiah, the future ingathering of Jewish exiles in Israel, and other ideas deemed insufficiently modern. The Union Prayer Book was a definitive ingredient of 20th-century classical Reform—its King James-style English was stentorian [and] its fragments of Hebrew few and far between; it rejected particularism in theology, while embracing Protestantism aesthetically.
Read more on Jewish Weekly: http://www.jweekly.com/article/full/75673/timeline-of-major-american-machzors/