Judaism
Around the 1st century CE, there were several small Jewish sects: the Pharisees, Sadducees, Zealots, Essenes, and Christians. After the destruction of the Second Temple in 70 CE, these sects vanished. Christianity survived, but by breaking with Judaism and becoming a separate religion; the Pharisees survived but in the form of Rabbinic Judaism (today, known simply as "Judaism"). The Sadducees rejected the divine inspiration of the Prophets and the Writings, relying only on the Torah as divinely inspired. Consequently, a number of other core tenets of the Pharisees' belief system (which became the basis for modern Judaism), were also dismissed by the Sadducees. (The Samaritans practiced a similar religion, which is traditionally considered separate from Judaism.)
History of the Jews in the United States
On a theological level, American Jews are divided into a number of Jewish denominations, of which the most numerous are Reform Judaism, Conservative Judaism and Orthodox Judaism. However, roughly 25% of American Jews are unaffiliated with any denomination. Conservative Judaism arose in America and Reform Judaism was founded in Germany and popularized by American Jews.