The article focuses on letters from the first austrian collection of emigrant letters, which is held at the University of Salzburg. It shows how these sources provide insights into migration processes and contribute to a deeper understanding of migration. The article discusses the advantages of using emigrants' letters to learn more about migration history, but also shows the limitations of these documents in historical research. The analyzed material comes from two writers who emigrated overseas from Austria in the 1950s because of the economic situation in the postwar period. For them migration meant an opportunity to improve living conditions. The one migrated to Argentina and stayed for life whereas the other migrated to North America and moved back to Austria twelve years later. They had different socioeconomic backgrounds, which led to different migration experiences and opportunities in the countries of destination. The political, legal, and economic situations in the countries of destination were different and the gender aspect must be considered in analyzing the letters. These contain a lot of information about the daily life of migrants and are important puzzle pieces for historical research. But the examples also show us the difficulty of letters as sources. Reconstructing the life of a person only through letters is like puzzle with pieces missing.