The statesmanlike moderation of Grand Duke Frederick won him universal esteem. By the treaty under which Baden had become an integral part of the German Empire in 1871, he had reserved only the exclusive right to tax beer and spirits. The army, the post office, railways and the conduct of foreign relations passed to the effective control of Prussia. In his relations with the German Empire, too, Frederick proved himself more of a great German noble than a sovereign prince actuated by particularist ambitions. His position as husband of the Emperor William I's only daughter, Louise (whom he had married in 1856), gave him a peculiar influence in the councils of Berlin. The Sonderbundskrieg had a significant impact on the psychology and society of Switzerland. The war convinced most Swiss of the need for unity and strength. Swiss from all strata of society, whether Catholic or Protestant, from the liberal or conservative current, realised that the cantons would profit more from merging their economic and religious interests. Thus, while the rest of Europe saw revolutionary uprisings, the Swiss drew up a constitution that provided for a federal layout. Article 11 of the constitution forbade sending troops to serve abroad, marking the end of foreign service. It came with the expectation of serving the Holy See.