McCaskill was raised in Chapin, South Carolina, where she attended Irmo High School.[1] She was twice-named to the All-State team and was the team's highest-scoring player in 2012 with 33 goals.[1] As a senior, she was ranked by Top Drawer Soccer in the top 100 players and top 20 midfielders nationwide.[2]
McCaskill played club soccer for CESA 95 in the Elite Clubs National League (ECNL) and captained the team.[1] She played for the South Carolina Olympic Development Program (ODP) team from 2008 to 2012 and the regional ODP team from 2010 to 2013.[1]
Collegiate career
McCaskill attended the University of South Carolina where she played for the Gamecocks from 2014 to 2017.[1] As a freshman, she started in all 25 matches and tied for the most points (15) on the team playing as a forward (though initially recruited as a defender).[3] She was named as Freshman of the Year by the Southeastern Conference (SEC) and was named to the conference's second-team and all-freshman teams.[4]
As a sophomore starting in all 25 games, McCaskill led the team in points and goals (29 and 10 respectively) while her nine assists ranked second.[1] She ranked in the top five in the SEC for points and assists per game as well as total assists.[1] She was named to the All-SEC First Team, NSCAA All-South Region First Team and was voted the team's Offensive Player of the Year.[1]
In 2016, McCaskill's 45 points and 17 goals set new school records for a single season.[1] Her ten game-winning goals ranked second in Division 1 and first in the SEC.[1] She was named the SEC's Offensive Player of the Week in early September.[5] She scored a hat-trick against Tulsa in August marking the first time one had been scored by a player on the team since 2010.[1]
McCaskill scored her first goal for Sydney FC in a 5–2 win over Adelaide United in December 2018,[12] before scoring a brace the following month against Newcastle Jets in a 3–1 win.[13]
Sydney FC advanced to the 2019 W-League Grand Final, Sydney won 4–2. McCaskill scored two goals and recorded an assist, she was named Player of the Match award for her performance.[14]
Chicago Red Stars, 2019–2020
On June 19, 2019, McCaskill was traded to the Chicago Red Stars in exchange for a first and second round draft pick at the 2020 NWSL College Draft.[15] McCaskill made her Red Stars debut on June 23, 2019, in a game where the Red Stars played Reign FC. McCaskill scored her first goal for the Red Stars in a 3–0 win over the Houston Dash.
Racing Louisville, 2021
Before the 2021 Season Chicago traded McCaskill as well as Yuki Nagasato's rights to Racing Louisville FC as well as a 2021 International Roster spot and the No. 5 overall pick in the 2021 NWSL Draft. McCaskill made her debut for Louisville on April 10, 2021, in their first game. She scored her first goal against her former team, Chicago Red Stars in a 3–0 win.
With the completion of the 2023 NWSL season, McCaskill became a free agent. On December 20, 2023, San Diego Wave FC announced the signing of McCaskill to a three-year contract.[17]