Texas is the first team in the modern era (after 1900) to score 30 runs in one game. (And all the runs came in four innings -- box!)
It was the ninth time a major league team has scored 30 runs, the first since Chicago set the all-time record in a 36-7 rout of Louisville in a National League game on June 29, 1897. The previous post-1900 record for runs in a game was 29 shared by the Boston Red Sox (1950) and the Chicago White Sox (1955). (The Rangers' previous high had been 26 runs, also against Baltimore on April 19, 1996 (26-7).)
Here is the 1897 linescore (more info on that game here):
Chicago 357 121 278 - 36 32 1(One of the very few times a team has scored in every inning! Also, the game was played in Chicago, but the Colts (later the Cubs) had the option of batting first, which they did.)
Louisville 001 050 100 - 7 14 9
With nine runs in the nightcap, the Rangers set an AL record with 39 runs in a single day. The major league record is 43: Boston beat Cincinnati 18-3 and 25-8 in an NL twinbill on August 21, 1894.
It reminds me of a minor league game on June 15, 1902: Corsicana beat Texarkana 51-3. (Justin Clarke hit eight home runs -- in eight consecutive at-bats.) Many newspapers got the wire report, assumed it was a typo, and reported the final score as 5-3.