Joseph P Kennedy Jr has an in memoriam headstone at Arlington National Cemetery next to his brothers, President John F. Kennedy, Robert F. Kennedy and Ted Kennedy.

When the new pathway was added for Ted Kennedy's grave in 2012, a memorial headstone was dedicated in honor of Joseph P. Kennedy Jr., who was the eldest of the Kennedy brothers.
Prior to his death, Joseph Kennedy was very much predicted to be the leader and politician in the family.
As the first born son of Joe Kennedy Sr., the U.S. Ambassador to the United Kingdom, Joseph Kennedy Jr. was encouraged to pursue politics after his service in the military.
However, he was tragically killed in a top secret mission during World War II. Due to his bravery and sacrifice, Joseph P. Kennedy was awarded the Navy Cross, Distinguished Flying Cross, Purple Heart, and Air Medal.
Following Joseph's death, John F. Kennedy, the second eldest of the Kennedy brothers, went on to fulfill those roles of leadership.
Unfortunately Joseph P. Kennedy Jr.'s remains were never recovered. However, in 2012 a cenotaph was erected in his honor.