1863 – Adler was born in Arkansas on September 13, 1863.
1887 – Graduated from the University of Pennsylvania and received his Ph.D. from Johns Hopkins University.
1892 – Founded the American Jewish Historical Society. He was appointed curator at the Smithsonian Institution in Washington, D.C..
1899-1905 – Served on the editorial board of the Jewish Encyclopedia.
1905-1908 – Appointed as the Assistant Secretary at the U.S. National Museum. Married Racie Friedenwald of Baltimore at the age of 42.
1908 – Accepted the post of President of the newly formed Dropsie College for Hebrew and Cognate Learning in Philadelphia.
1940 – Died in Philadelphia on April 7 at the age of 77.