"Capped die" Morgan dollars occurred only in 1879 and only on CC mintmark coins. The term has nothing to do with grading or with certified coins. The mintmark is repunched - two different sizes of CC mintmark were punched into the die. For 1879CC, this repunched mintmark acquired the popular name "capped die".
An 1879 "Silver Dollar" is a Morgan dollar.
Actually no, values are a little lower per grade for this type.
1879 would make it a "Morgan" dollar.
The 1879 Morgan dollar has a diameter of 38.1mm, thickness is 2.4mm.
This link shows a 1879 Morgan Dollar: http://www.coinfacts.com/silver_dollars/morgan_dollars/1879_morgan_dollars/1879_morgan_dollar_obv.jpg
An 1879 S Morgan dollar in MS(Mint State)63 condition is worth somewhere around $64. This is a common date.
A 1879-S Morgan Dollar in MS60 condition is worth: $45.00.
Peace dollars were made from 1921 to 1935. An 1879 silver dollar is called a Morgan dollar after its designer George T. Morgan. There's more information at the Related Question
The 1879 Morgan dollar is not scarce or rare, assuming it's circulated and has no mintmark, average retail values are $26.00 to $32.00 depending on how much wear the coin has.
The 1879 Morgan dollar is not scarce or rare, assuming it's circulated and has no mintmark, average retail values are $30.00 to $41.00 depending on how much wear the coin has.
All 1879 issues have 7 tail feathers.
A certified example of the Philadelphia issue 1879 Morgan in MS-66 has a average retail value of $2,750.00