On April 25, 1865, Robert Lincoln wrote President Andrew Johnson requesting that he and his family be allowed to stay for two and a half weeks because his mother had told him that "she can not possibly be ready to leave here." Lincoln also acknowledged that he was aware of the "great inconvenience" that Johnson had since becoming president of the United States only a short time earlier. Following his father's assassination, in April 1865 Robert moved with his mother and his brother Tad to Chicago. He attended classes at the Old University of Chicago law school (later absorbed by Northwestern University's School of Law, now called the Northwestern University Pritzker School of Law) and studied law at the Chicago firm of Scammon, McCagg & Fuller. He was admitted to the bar on February 25, 1867. On January 1, 1866, Lincoln moved out of the apartment he shared with his mother and brother. He rented his own rooms in downtown Chicago to "begin to live with some degree of comfort" which he had not known when living with his family. Lincoln was licensed as an attorney in Chicago on February 22, 1867. He was certified to practice law four days later on February 26, 1867.