Who Was The First Embedded Journalist?

The term "Embedded Journalist" did not come into being until the invasion of Iraq in 2003. I do not believe that there is any single reporter that carries that distinction as being the first.
There were earlier War Correspondents, such as Ernie Pyle, that traveled, ate, and slept with the Combat Troops, but they would not fit the description of Embedded Journalists. To be one of those you have to sign a contract with the military and follow all of the rules that this authority sets down,. All of this reporting is subject to censorship by the US Government.
There is no such thing as "Freedom of The Press" as an "Embedded Journalist".
Only what the military wants reported, is reported.
In return, the Embedded Journalist is under the protection of the Unit to which they have been Embedded in.