Thanks to Baseball Almanac, I found the list of every player to have accomplished the feat. Not surprised to see that Honus Wagner and Ty Cobb each did it 4 times. Only two other players, Max Carey and Jackie Tavener, had done it more than once. Overall, there have been 50 occasions where a player has stolen three bases in a single inning. Just twice was it recorded in a year prior to 1900. In fact, it has been done twice in the American League and 24 times in the National League. Some greats to have done it include Rod Carew, Pete Rose, Rogers Hornsby, Eddie Collins and Joe Jackson. As expected, of the 50 times the feat had been accomplished, 39 of them were recorded in the year of 1928 or earlier.
The most interesting fact I noticed about this feat is that out of the 11 times it has happened since 1928, 5 of the instances were AFTER Molitor did it on the date in 1987. So, that means it happened 39 times from 1899-1928, 6 times from 1929-1987 and 5 times from 1988-now. The longest amount of time that passed between such an occurrence was from the years of 1941 (Don Kolloway) and 1969 (Carew).
Since Molitor on July 26, 1987, here are the more recent players to have stolen 2nd, 3rd and home in the same inning:
9/9/1989- Devon White, Toronto Blue Jays
5/12/1996- Chris Stynes, Kansas City Royals
6/30/1996- Eric Young Sr, Colorado Rockies
5/12/2009- Jayson Werth, Philadelphia Phillies
7/1/2011- Dee Gordon, Los Angeles Dodgers
Of course, not all players to steal three bases in an inning did it the conventional way of three conventional steals. Some of the occurrences are on double steals of both 3B and home which some can say does not count the same way. But, in the books, it is still recorded the same way.