What is the lowest ranking military branch Army or Marines?

Answer 1

Branches are not ranked. They are considered equal and with different missions.

AnswerThe ranking of branches is a ceremonial thing. In a joint service parade, ranking helps the units form up the parade.

The Army, as the oldest service, is first, followed by the Marines, the Navy and the Air Force.

To answer the original question, the Marines rank lower than the Army in precedence. The Air Force brings up the rear in a line of march except when during a parade the Coast Guard is present, war is not declared, and it is operating under the leadership of the Department of Homeland Security. At those times the Coast Guard is the Junior Service.

The document to research is DoD Directive 1005.8 which may (or may not) explain why the Senior Service is questioned even today. Because the Army began as a mixture of militia units and Continentals and the US Navy had no ships (even in the design stage) they did not exist as a Federal armed force. The Marine Corps was to be a very small force, was quickly recruited (mostly in taverns) was cohesive and quickly trained and received the first paychecks, they use that as a claim for first in Federal Service.

Answer 2

The Marines is technically a part of the Navy Department and has the lowest number of personnel compared to the Army. However, in terms of rank structure and hierarchy, both the Army and the Marines have similar ranks and should not be differentiated as higher or lower in ranking.