Simplify the following text for a Grade 6 native English-speaking person.
Original: He went to the front to observe the Franco-Prussian War in 1870 , and , after being taken prisoner at Vaucouleurs , remained in French captivity for three months .
Simplified: Then he went to write about the Franco-Prussian War in 1870 and was taken prisoner . He remained in French captivity for three months .