Amos Anderson donated Tamminiemi to the state in 1940 for several reasons. Firstly, he wanted to ensure the house's preservation and use for the benefit of the Finnish people. The donation was made on the condition that the City of Helsinki extended the lease on the plot, which was set to expire in 1942. Additionally, Anderson's personal friendship with President Kyösti Kallio played a role in his decision, although Kallio passed away before he could move into Tamminiemi. Anderson was a patron of the arts and the owner of Finland's largest Swedish-language newspaper, Hufvudstadsbladet, and his donation reflected his commitment to the cultural heritage of Finland. Since then, Tamminiemi has served as the official residence for several Finnish presidents.