Lawyers from other countries can and do come to practice in the US. It typically means getting an extra degree (LL.M.) and taking the state bar exam, but I've known a few people, particularly transactional lawyers from Canada, who seem to have made this transition. In general it would be easier coming from a common-law country like Canada, UK, Australia, etc.
"In order to sit for the bar examination, most states require an applicant to hold a Juris Doctor (J.D.) degree from an American Bar Association (ABA)-approved law school. For those individuals who have not earned a J.D. degree from an ABA-approved law school, bar admission authorities have developed varying requirements and criteria to ascertain if such individuals meet the minimum educational requirements for bar admission. In most U.S. jurisdictions, individuals who lack a J.D. are ineligible to take the bar exam..."
