Historical Writings:
* Geschichte des Rheinlandes vom Anfange der fränkischen Herrschaft bis zum Ende des 17. Jahrhunderts (History of the Rhineland from the Beginning of Frankish Rule to the End of the 17th Century) (1885-1892): This multi-volume work is considered his magnum opus and remains a valuable source on the history of the Rhineland.
* Die Geschichte der rheinischen Städte im Mittelalter (The History of Rhenish Cities in the Middle Ages) (1869): This book examines the development of cities in the Rhineland during the Middle Ages.
* Die Verfassungsgeschichte der rheinischen Städte im Mittelalter (The Constitutional History of Rhenish Cities in the Middle Ages) (1871): A detailed study of the political institutions of Rhineland cities during the Middle Ages.
* Preussen und die Rheinlande (Prussia and the Rhineland) (1882): This book analyzes the relationship between Prussia and the Rhineland during the 19th century.
* Geschichte der deutschen Nation (History of the German Nation) (1887): A comprehensive overview of German history.
Other Writings:
* Die Entwicklung des deutschen Staatsrechts (The Development of German Constitutional Law) (1865): A work on the development of the German legal system.
* Die Verfassung des Deutschen Reichs (The Constitution of the German Empire) (1874): A commentary on the German Empire's constitution.
Bachem's historical works were highly regarded in his time and continue to be studied by historians today. He is considered an important figure in the development of Rhineland historical scholarship.