The actuarial profession in North America began in the early 19th century, built upon principles that had been used in Europe since the mid-17th century. During the last decade of the 19th century, there were less than 100 North American actuaries, though the numbers were growing. The Society of Actuaries traces its roots to the Actuarial Society of America, which was formed by a select group of chief actuaries at well-established life insurance companies. In 1909, their counterparts at newer life insurance companies formed the American Institute of Actuaries. In 1949 these two groups merged to form what is now the Society of Actuaries. Today the SOA boasts a membership of 20,000 in the United States and Canada.