Pipestem found in our front yard with 1874 patent?

We live in a subdivision in Austin, Texas that was finished in 1978. A few weeks ago, a large city water pipe broke in our yard and the city dug down with a backhoe 5 or 6 feet deep. They filled it back in and I was looking at some loose dirt today and found a black pipe stem that is curved and marked on the left edge "Patented March 3, 1874". I can tell that it is broken where it would have mated with the bowl, maybe it was a screw on type bowl? I had to clean the mud out of the mouthpiece and found a reference to a U.S. patent issued on that day to L.G. Hussman.