The US Open is investing $600 million to upgrade its grounds in Queens where the season’s final Grand Slam event gets under way on Monday.

Here are other key dates in the history of the tournament:

1968: Arthur Ashe and Virginia Wade win the first-ever US championships to permit both amateurs and professional players. Prior to that year, only amateurs could compete.

1978: The US Open moves from the clubby West Side tennis club at Forest Hills to the public Flushing Meadow-Corona Park, also in Queens, but with a much more egalitarian vibe. The tournament opts for a hard court with a true bounce, avoiding grass and clay, the surface of choice at the other tennis Grand Slams.

1984: “Super Saturday” goes down as one of the greatest days in tennis history, with Ivan Lendl beating Pat Cash and John McEnroe outlasting Jimmy Connors in men’s semifinal matches. Sandwiched in between, Martina Navratilova edges Chris Evert for the women’s championships. All three matches go the distance.

1988: Steffi Graf defeats Gabriela Sabatini to become only the fifth player to win a calendar year Grand Slam.

1997: The USTA unveils Arthur Ashe stadium, the largest tennis stadium in the world, replacing the original center court, which was named for one of Queens’ most famous residents, Louis Armstrong.

An unseeded 17-year-old Venus Williams reaches the final of the women’s championship, losing to Martina Hingis and announcing the arrival of one of the most dominant sibling acts in sports history. Her sister, Serena Williams, would win her maiden Grand Slam championship in New York two years later, the first of Serena’s 22 championships so far.

2004: Roger Federer defeats Lleyton Hewitt in the final, an early marker of a men’s tennis era with several all-time greats. Between them, the “Big Four,” which consists of Federer, Rafael Nadal, Novak Djokovic and Andy Murray, have won all but two of the mens’ crowns since 2004.

2005: The US Open replaces its green courts with blue to make the yellow-green balls easier to pick up for players and fans.

2008: The National Tennis Center takes the name of Billie Jean King, honoring a tennis legend and a pioneer in women’s equality through sport.

2016: The US Open unveils a roof over Arthur Ashe Stadium, the crown jewel of a $600 million expansion intended to position the tournament for the coming decades.