I'm just speaking up here to contribute some Educational info.
Note that the lettering in that Texas button's "Extra Quality" backmark does not have serifs on the letters. (For anybody who doesn't already know, serifs is the name for the little tabs on the ends of a letter's arms.) Any of the variations of "Quality" backmarks (Extra Quality, Superior Quality, Fine Quality, Superfine, etc.) that doesn't have serifs on the letters is from the 1880s or later.
Check the link Bell generously provided in his post (above). That webpage shows many examples of CIVIL WAR (and earlier) "Superior Quality" backmarks. Look closely and you'll see that ALL of them have serifs in the lettering.
http://relicman.com/buttons/zBackmarkSuperiorQuality.htm
According to the book "American Military Button Makers And Delers; Their Backmarks & Dates", the time-dating rule about serifs in the backmark's lettering also applies to business-name backmarks. According to that book, there is only ONE exception to that rule. The single exception is one of the many varieties of Horstmann backmarks ...specifically, "Horstmann / N.Y. & Philada" ...which dates from 1865-through-1870. Apart from that single exception, a no-serifs backmark means the button is post-civil-war era.
For anybody who needs to see some examples of serifed and non-serifed lettering... here are two images. The first is a graphic done by TN's own BigCypressHunter. The second shows serifed and non-serifed lettering on four modernday FAKE "slave tags" for sale on Ebay.
