The first cover, postmarked 19 June 1967 from Libenge to Illinois, uses stamps showing two different names for the country. Formerly Belgian Congo, it gained independence in 1960 as Republic of Congo (same name as the French Congo after independence). In 1965 the name was changed to Democratic Republic of the Congo.

Leonard Nyberg (1916-2010) was born in Polk, Nebraska and moved to Rockford, Illinois when he was 23. He married LaVerna Ang in 1942, and served in the Army Air Corps from 1941 to 1945. He was a member of the First Evangelical Free Church.

He and his wife received letters sent by locals who were doing missionary work in the Congo. The Lindquists were with the Evangelical Covenant Church, and were in the Congo till 1969. The second cover is postmarked Leopoldville, the capital city (now Kinshasa).