Answering your two questions:
Yes, it is a protector for the toe end of a shoe's leather sole.
It was invented and patented in 1859. Some of them have the Patent-date stamped into the brass, like the example in the photo below, marked "Pat. Nov.29, 1859."
Time-dating yours:
Of course, they were manufactured for many decades after the Patent-date. Ones made during the patent's "lifespan" (at that time, 14 to 17 years), they were marked with the Patent-date. After the patent expired, anybody could manufacture them without having to pay the inventor a fee, so there was no need for patent marking after it had expired. Look closely to see if yours has the Patent-date. If not, it was made sometime after November 1876.