July 10 In Swedish History
1877: Stockholm’s first tramway opens when Stockholms Nya Spårvägs AB (a company that exists between 1876-1917) puts its first horse-drawn cars in traffic. These horsecars were replaced by regular trams after 1905. After Stockholm, horsecars were introduced in Göteborg in 1879 and in Malmö in 1887.
The company, Stockholms Nya Spårvägs AB's concession to build and traffic Stockholm was transferred to AB Stockholms Spårvägar in 1917.

We've covered aspects of the Stockholm tram system in Leif Rosqvist's Walkabout tours of Stockholm, for instance here: Walkabout Tour of Stockholm I .. walk in the city of my youth