Only a few thoughts to add to those already offered - some I can document and others I can't.
Stanlaurel, the pix of MacArthur smoking his pipe wearing Captain insignia was taken, I believe, during the occupation of Veracruz in 1914. By the time he landed in France in 1918 he was a full bull colonel.
https://en.wikipedia.org/wiki/Douglas_MacArthur
Like Pappymac, I've read that MacArthur grabbed the long stemmed corncob for photo ops. His smoke of choice were those oily, black as midnight cigars made in the Philippines. (There was a tele-evangelist, Gene something or other, who smoked a similar cigar back in the early 80's. He was quite a character and used to reference MacArthur.)
MacArthur threw Gen. James "Skinny" Wainwright under the bus and then backed over him a few times. Wainwright was the general MacArthur gave the defense of the Philippines to after he was recalled to Australia. However, MacArthur received the CMOH in early 1942 (the first and only father and son award winners) but fought off Gen. George Marshall's recommendation to give Wainwright the same honor later that year. Fortunately, Wainwright did receive the CMOH from President Truman in 1945.
http://www.historynet.com/a-dreadful-step-surrender-at-luzon.htm
http://www.homeofheroes.com/brotherhood/generals_2.html
MacArthur did indeed violently break up the Veteran's March/Encampment in Washington, as Jiminks recalled, and he also sat in on the court martial of Gen. Billy Mitchell.
It's really hard to recall a leading military figure in U.S. history who was so polarizing. Our fathers and grandfathers served under him and some of those guys are pretty damned opinionated. Years later he was fired by President Truman during the Korean Police Action for numerous transgressions: foremost being when POTUS tells you to stop at the Yalu River and you decide to press on - well then, Bob's your uncle.
And still, MacArthur's swan song in 1962 at the West Point dining hall always gets me a little emotional:
"The shadows are lengthening for me. The twilight is here. My days of old have vanished, tone and tint. They have gone glimmering through the dreams of things that were. Their memory is one of wondrous beauty, watered by tears, and coaxed and caressed by the smiles of yesterday. I listen vainly, but with thirsty ears, for the witching melody of faint bugles blowing reveille, of far drums beating the long roll. In my dreams I hear again the crash of guns, the rattle of musketry, the strange, mournful mutter of the battlefield. But in the evening of my memory, always I come back to West Point. Always there echoes and re-echoes: Duty, Honor, Country. Today marks my final roll call with you, but I want you to know that when I cross the river my last conscious thoughts will be of The Corps, and The Corps, and The Corps. I bid you farewell."
Lord knows he was flawed, but he truly loved his country.
Fnord