Original: In another famous example, the Boston Americans (an unofficial designation that merely distinguished them from their across-the-tracks rivals) adopted the Nationals' abandoned red stockings in , and have been the Boston Red Sox officially ever since then.
Simplified: In another famous example, the Boston Americans (an unofficial name that made it easier to tell different teams apart) used the Nationals' red stockings in 1908 since the Nationals did not use them anymore. They have been called the Boston Red Sox ever since.