Passage: Frederick Engels took part in the uprising in Baden and the Palatinate.  On May 10, 1848, he and Karl Marx traveled from Cologne, Germany, to observe the events of the region.  From June 1, 1848, Engels and Marx became editors of the Neue Rheinische Zeitung. Less than a year later, on May 19, 1849, the Prussian authorities closed down the newspaper because of its support for constitutional reforms.

Question: In which year did Karl Marx travel with him?
1848