Complex sentence: Frederick William Seward (July 8,1830--April 25,1915) was the Assistant Secretary of State during the American Civil War, serving in Abraham Lincoln's administration as well as under Andrew Johnson during Reconstruction and for over two years under Rutherford B. Hayes.
Split into simpler sentences: Frederick William Seward (July 8,1830--April 25,1915) was the Assistant Secretary of State during the American Civil War, serving in Abraham Lincoln's administration. He held the same post under Andrew Johnson during Reconstruction and for two years under Rutherford B. Hayes.