He was portrayed by Kirk Douglas in the 1966 Hollywood movie Cast a Giant Shadow, which focused on his role in the Israeli war.

He was assigned to the Civil Affairs Division, as chief of planning for occupation governments in territories liberated from the Axis.

He accompanied U.S. delegations to the conferences at Cairo, Teheran, Yalta and Potsdam, and helped draft the 1943 surrender terms for Italy.

[6] After V-E Day in 1945, General Lucius D. Clay asked for Marcus to serve on his staff in the occupation of Germany.

After the trials, he was offered promotion to brigadier general, but instead elected to return to civilian life and his law practice.

[6][9] In 1947, David Ben-Gurion asked Marcus to recruit a U.S. officer to serve as military advisor to the nascent Israeli army, the Haganah.

In 1948, the National Military Establishment informally acquiesced to Marcus' undertaking, provided he disguised his name and rank to avoid problems with the British authorities in Mandatory Palestine.

As no ranks had been granted to the Israeli high command at that time, he became the first general in the fledgling nation's army (see Israel Defense Forces).

)[12] He participated in planning Operations Bin Nun Bet and Yoram against the Latrun fort, held by the Arab Legion, which blocked the road from Tel Aviv to Jerusalem, which was under siege.

His "Burma Road" was opened to vehicles on June 10, breaking the siege of Jerusalem, a day before a United Nations ceasefire took effect.

He and his commanders were billeted in the monks' quarters of the abandoned Monastere Notre Dame de la Nouvelle Alliance in Abu Ghosh.

On the same day Marcus was shot, Ben-Gurion summoned Yaakov Shimshon Shapira—later Israel's Attorney General—and asked him to investigate the incident.

His gravestone at West Point reads: A memorial plaque in his honor is located in the lobby of the Union Temple of Brooklyn where his funeral service was conducted.

[23] In January 2015 Israel's President, Reuven Rivlin, visited the United States Military Academy at West Point and spoke at Marcus' grave: Kibbutz Mishmar David and the neighborhood of Neve David in Tel Aviv as well as numerous streets are named after him.