When the United States entered World War I in the spring of 1917, Muck offered to resign his position as music director of the BSO. He anticipated that his natural sympathies for Germany, where he was born and spent most of his career despite his Swiss citizenship, might give offense. Henry Lee Higginson, the orchestra’s founder and financer, declined it and instead signed Muck to another five-year contract. Muck had fears for his own safety, but Higginson gave him assurances that as an artist he had nothing to fear. Thereafter he became very sensitive to avoid giving offense. The orchestra's publicity manager later wrote: "A good and patriotic German, he had become greatly attached to this country, and altogether he was a thoroughly unhappy man." Nevertheless, he programmed all-German concerts on his first tour of American cities following U.S. entry into the war, which some found not at all sensitive to the public's mood in wartime.