Timeline memorization forms an important component of our school's curriculum. Among other things, our middle school U.S. History students memorize this presidents timeline, which includes each president's years in office and party affiliation. I found it helpful to type up the information in a no-frills, easy-to-read list which the students could keep in their notebooks.
I generally assign the students 5 presidents per assessment. It is helpful to have them memorize the complete timeline as early in the year as feasible so they can place the events you study throughout the year in context.