Simplify the following text for a Grade 7 native English-speaking person.
Original: Mary Ann ( nÃ e Todd ) Lincoln ( December 13 , 1818 â `` July 16 , 1882 ) was the wife of the 16th President of the United States , Abraham Lincoln , and was First Lady of the United States from 1861 to 1865 .
Simplified: Mary Ann Todd Lincoln ( December 13 , 1818 - July 16 , 1882 ) was the wife of Abraham Lincoln , the sixteenth President of the United States . She acted as the First Lady of the United States from 1861 until 1865 .