Complex sentence: In 1849, Abigail Fillmore came to Washington, D.C. as wife of the Vice President; 16 months later, after Zachary Taylor's death at a height of sectional crisis, the Fillmores moved into the White House.
Split into simpler sentences: In 1849, Abigail Fillmore came to Washington, D.C. as wife of the Vice President. Sixteen months later, after Zachary Taylor's death at a height of sectional crisis, the Fillmores moved into the White House.