Not drinking has become more common in America, but it is still often important for work/career advancement...especially sales jobs. Sometimes colleagues get together after work, drink, and then form bonds and/or exclusionary social groups through this after-hours socializing. You could attend without drinking, but it might not have the same effect.
Many people nowadays don't drink for secular reasons (health and $, mostly). If someone doesn't drink because of religious reasons, most decent people will respect that. Generally, America is quite tolerant of other cultures; depending on what sector you work in, Americans of European decent are often less than 50% of the work force (manufacturing, engineering, tech, science/labs, medicine).