Cortesio, the only woman umpire in organized baseball, is hoping to open doors for others to follow her in a pursuit she was determined to undertake as far back as high school. But she in no way considers herself a trail blazer in the fashion of Pam Postema, who called balls and strikes with passion in the 1980s.
"Until I work a regular-season Major League baseball game, I haven't done anything," Cortesio said, "I don't want to be a pioneer. I just want to do my job.
"It really doesn't make any difference [being a woman] on the field -- or even off the field. I do feel a great responsibility to get girls and women involved."
She did her job on Sunday as professionally as she has throughout her career, according to a fellow umpire, Jason Stein, who worked the game alongside his old partner from the Pioneer League in 2000.
"She's good enough to be here," said Stein, who works the Double-A Texas League. "She's just as good as we are. If she gets the opportunity to advance to the big leagues and be successful, it would be a great thing. I'm pulling hard for her.
"I'm not an umpire evaluator, but I've been around her enough to know how good she is. As long as it's somebody who works hard and does the job well, nothing else should matter. I want all of my partners to make it to the big leagues."
A native of Davenport, Iowa, who graduated from Rice University, Cortesio is one of five women to have umpired in professional baseball. Postema came closest to reaching the Major Leagues when she worked Spring Training games in the late '80s.
Cortesio's immediate goal is to be granted a promotion to Triple-A, since it is one step at a time in her business and, "I can't score from second without touching third." Home plate would be the Major Leagues.
"That would be something," she said. "It's an honor to be here -- it's like Christmas for us to get selected. To get to the big leagues, that would be the same as a player or anybody else -- that's the goal, the top. Anyone in my profession wants to get to the top.
"But my goal right now is Des Moines ... to be a Pacific Coast League umpire."
Cortesio, who will work one of the foul lines in Monday night's Home Run Derby, was selected out of a pool of Double-A umpires for the assignment.
She said nothing unusual happened on the field Sunday or in interactions with fans, adding that she was so focused on her work that she didn't have time to consider her surroundings.
Players such as World catcher George Kottaras, with whom she interacted during his time with Mobile in the Southern League, have treated her with utmost professionalism.
"The one group of people that I haven't had a single problem with are the players, coaches or managers," Cortesio said. "If anything, there are some that are more respectful to me than usual."
Asked what drove her as a young person to become an umpire, and to continue to hold that dream through college, she referred to "the challenge."
"I don't think that people realize what a challenge it is to work games day in and day out at the professional level, always on the road," she said.
"It's you against the world during the season. That's why you feel so close to your partners. You're in it together."
Cortesio began the season as a substitute teacher with Minor League umpires on strike, and returned to the job after it was settled. They are given $25 a day per diem, a far cry from the $357 (also covering hotels) awarded Major League umpires.
With turnover slow on the 68-man Major League umpiring staff, Cortesio knows it's a long road to the big time. She grits her teeth and continues to accept the challenge, determined to show she's good enough to do the job she always wanted.