In a compelling new biography, part of The American Presidents series edited by Arthur M. Schlesinger Jr., Ira Rutkow makes us care about a forgotten president, James A. Garfield, who served only four months in 1881 before he became the second president to be assassinated.

Today, Garfield is reduced to a few sentences in high school history texts. But in his compressed but comprehensive book, “James A. Garfield” (Times, $20), Rutlow, a historian and surgeon, skillfully outlines Garfield’s achievements. He was a college president, Civil War general and U.S. congressman by age 32. Seventeen years later, Garfield became one of the youngest presidents to take office.

Rutkow is most effective describing the improbabilities of a poor boy becoming the last president to go from a log cabin to the White House. He shows how Garfield used his humble beginning as an asset to charm voters and politicos alike. Early on, Garfield attracts powerful men, from a college president to President Lincoln, to mentor him.

Rutkow also captures a restless Garfield always searching for new goals. He read prodigiously, checking out more books than any other congressman. He amazed friends “by simultaneously writing Greek in one hand and Latin in the other.”

Perhaps in time, Garfield would have answered his critics with wise decisions as Lincoln did. In his first months of office, Garfield’s administration saved the federal government millions of dollars a year by renegotiating the national debt and reducing interest payments. But Garfield only had about 120 days in office before a deranged office seeker shot him at a time when U.S. presidents didn’t have an army of Secret Service agents.