First vice president to become president upon the assassination of his predecessor?

Answer 1

Chester Alan Truman was the second. The first was Harry Truman

Don't think so! The correct answer is CHESTER ARTHUR. From a Wikipedia article:

James A. Garfield assassination

James A. Garfield was shot in Washington, D.C. on July 2, 1881 by Charles J. Guiteau at 9:30 a.m., less than four months after taking office as the twentieth President of the United States. Garfield died eleven weeks later on September 19, 1881, the second of four Presidents to be assassinated, following Abraham Lincoln and preceding William McKinley and John F. Kennedy. His Vice President, Chester Arthur, succeeded Garfield as President.

Answer 2

John Tyler

He became president just 30 days after he and William Henry Harrison took office. Harrison fell ill after giving his inaugural address and died 30 days later.

http://www.patriotstoolbox.org/america/presidents/johntyler.htm

Answer 3

Andrew Johnson, Lincoln's Vice President.

Answer 4

April 6, 1841 -- John Tyler 1.First vice president to assume the presidency due to the death of the president.

Answer 5

John Tyler became President upon the death of William Henry Harrison in 1841.

Answer 6

John Tyler, after William Henry Harrison died.

Answer 7

John Tyler was the first vice president to ascend to presidency upon the president's death. He was vice president to William Henry Harrison, who died in 1841.