I am presenting this as a hypothetical case, but it is very close to my actual situation.

A relative died intestate in September 2014. As an heir, I was to receive all the decedent's shares in ABC Corp, which as of date of death was 1,000 shares, valued at $10 per share. Because of a long probate case, the shares were held in an estate account for just over one year before I took possession of them. During that period, ABC Corp paid out quarterly dividends, which were reinvested. Consequently, by the time I received the shares, there were 1,100 shares, now valued at $15 per share.

My understanding is that inherited shares are all treated as long term, and that clearly should apply to the original 1,000 shares. But what about the additional 100 shares acquired via reinvested dividends over the 12 months following the date of death? Are they long term or short term?

I have searched the web in vain trying to find an answer to this question, so I would appreciate any help.