Well I have a Union Pacific DD40X with roadnumber 6922 (HO) and I think it might be out of one of the Centennial train sets from the early 80s.  Because the engine and the box that it's in looks like the same as Bachmann 1983 Catalog ad image. The ad I speak of can be found here,
http://www.ho-scaletrains.net/bachmannhoscalelocomotives/id54.html
White box out lined in yellow, the Bachmann name is in all caps top left corner and next to that it says HO in yellow inside a little red square. Engine has a light gray roof and a black railing around it's deck.  The box does not have a black sticker on it telling me what it is. 
Reason I wanted to know is I thought about  putting together the original set if it is in fact out of the Centennial  train set.  I don't think this is one of Bachmann's top line trains but I figured it was a good train for a beginner like me to start with.  Not to mention it was never used an I got it for almost nothing.

Hello,
        I was wondering how or if there was a way to tell when a Bachmann train was made by the box that it is in, like TYCO has the Blue box (1950s), Red box (1960s) and Brown box (1970s).  Especially the trains that came in sets that were individually boxed inside the main set box.  These boxes don't seem to have any numbers or date on them.  How do you look at the engine or cars and tell how old they are?
I was trying to find any post on this but I couldn't.
  If this topic was already covered could someone link it to me please.

Baseball cards?  but they don't do anything, why would you want them. lol  Thanks guys I think I am going to use it. I am in no hurry to open it since I am starting from scratch building my layout, an seeing I have no clue it might be a while lol.

Hello, I am new to here and to HO trains.  I had some sets when I was younger, but nothing but just a couple of trains and a track.  The other day I dug out my old trains and some stuff that's been pasted down to me and I want to build a layout.  
Anyways I wanted to ask this question, I have a Bachmann Bicentennial set that has never been opened, and I was thinking about using it but I have no clue what it's worth and I hate to ruin the value by opening it.  I been doing web searches and can find nothing to compare it too.  Ebay has some used cars but that's about it.  What scared me was that I seen a BACHMANN THOMAS JEFFERSON BICENTENNIAL 51' BOX CAR - N SCALE #5205 for $698.75 on Amazon, and yea that is N scale. So back to the question should I open it or not.
BTW, I also got Tyco's, Alco 430 Diesel in Spirit of '76 and the Twin F9 Diesels Spirit of '76 plus some Commemorative State box cars.  Just another reason I wanted to open it.