In 1902 he founded the Saxon Manufacturers' Association. In 1903 he married Käte Kleefeld (1885-1970), daughter of a wealthy Jewish Berlin businessman. At that time he was also a member of Friedrich Naumann's National-Social Association. In 1906 he was elected to the Dresden town council. Though he had initially worked in trade associations, Stresemann soon became a leader of the National Liberal Party in Saxony. In 1907, he was elected to the Reichstag, where he soon became a close associate of party chairman Ernst Bassermann. However, his support of more social-welfare programmess was not popular with some of the party's more conservative members, and he lost his post in the party's executive committee in 1912. Later that year he lost both his Reichstag and town council seats. He returned to business and founded the German-American Economic Association. In 1914 he returned to the Reichstag. He was exempted from war service due to poor health. With Bassermann kept away from the Reichstag by either illness or military service, Stresemann soon became the National Liberals' de facto leader. After Bassermann's death in 1917, Stresemann succeeded him as party leader.