Alan Cooper Spaulding was born in the summer of 1999 to the wealthy Phillip Spaulding and his working class wife, Harley Cooper. Born in the wake of his grandfather Alan's heart attack, the child was named after Phillip's adoptive father, Alan Spaulding. Days after his birth, Harley decided to nickname the boy "Zach" from a character in one of Phillip's early novels about a young artist who declared his freedom from his wealthy family. Unfortunately, Zach's family life would be torn apart less than a year later, in 2000, when it was discovered that Phillip had had an affair with Beth Raines and the child she was carrying was his. After the birth of Beth and Phillip's child, James, Harley decided she couldn't forgive Phillip for his infidelity and she left him. In early 2001, she decided to divorce him and sought custody of Zach. Though Phillip tried futilely to change Harley's mind, she was adamant. Out of respect for her, Phillip allowed Harley to keep the house that he'd bought for her. The dissolution of her marriage led to Harley seeking comfort in the arms of Phillip's best friend, Rick Bauer and conceiving his child. Late that summer, Zach gained another little brother--Jude. In 2002, after almost a year of them getting to know each other, Harley invited Gus Aitoro to move in with her and the kids. Gus soon bonded with the boys who, in turn, adored him. Unfortunately, Phillip didn't trust Gus and after learning that Gus had a juvenile record, he threatened to seek custody of Zach unless Gus was thrown out. When a stubborn Harley refused to even look at Gus's juvenile file, Phillip took Zach to live with him at the Spaulding mansion. Angry, Harley retaliated by kidnapping Zach, When Phillip demanded that Harley be arrested, the chief of police complied and Harley was forced to choose between leaving Zach with Phillip or social services. Harley reluctantly agreed to let Phillip continue to care for Zach while she fought for custody. The custody battle waged on for several months. With no resolution in sight, things came to a halt when Zach accidentally ran into the street and was struck by a car in the spring of 2003. Luckily, Gus was on the scene, and saved Zach by transporting him safely to the hospital. Grateful, and feeling guilty about everything, Phillip dropped his custody suit. In 2004, Zach looked forward to Gus marrying Harley and was hurt when it didn't happen. Although Zach was angry at Gus, blaming him since Gus told them they'd be a family, Gus was able to win him over and Zach forgave him.

In the meantime, Phillip was waging his own private vendetta against the Cooper family, mainly by threatening to have the Cooper family restaurant "Company" destroyed. Although the Coopers tried to shield Zach from their problems, Zach caught on that Phillip was trying to hurt his mother and distanced himself from him. Although the Coopers (with help from Gus and Beth) were able to keep Company, it cost Zach his home when Phillip vindictively demolished Harley's house. In the next several months, the war between the Coopers and Spauldings heated up with Harley disguising herself as "Ruth" in order to spy on Phillip. Although everyone else was fooled by the disguise, Zach recognized her immediately but agreed to keep it a secret. Unfortunately, Zach later innocently told his father who "Ruth" really was, causing Phillip to kidnap all of his children. Although the children were later found by Gus, Zach was devastated to learn that his father was dead. For the next several months Zach was consoled and taken care of by his family. In 2005, Harley was arrested for Phillip's murder, but all Zach, who was staying with the Coopers, knew was that his mother was going away for a long time. Before going to prison, Harley tried to make the boys understand that she had to leave, but an angry Zach responded by trying to run away. Luckily, Gus stopped him and helped reconnect with his mother. After spending a horrible summer missing his mother, the pair were joyfully reunited that after Harley was finally exonerated for Phillip's murder. In addition to finally having his mom home for good, Zach was happy when she and Gus finally wed.

Unfortunately, things wouldn't go as planned. In early 2006, less than five months after the wedding, Gus disappeared. When Zach kept asking when Gus would come home, Harley insisted that it would be soon. However, Gus planned a family vacation for the entire family in Hawaii and Zach was concerned he wouldn't be back in time. Harley insisted that Gus would be there. Later, Harley was forced to tell the kids that Gus had been involved in an accident and was dead. Fortunately, Gus wasn't dead after all; and after having been missing for almost two months, returned to the family. Unfortunately, things still didn't go back to normal. When he was gone, Gus had been injured and ended up being addicted to pain medication. Attempting to wean himself off the pills, Gus and Harley went to the deserted cabin so he could detox. There, Harley calmed Gus by reading him a story that Zach had written. Thus, Zach played a pivotal role in Gus's recovery. Unfortunately, recovery would prove harder than he thought and Gus would relapse after a trip to San Cristobel. Gus's condition, or his arguments with Harley, didn't go unnoticed by Zach. When Jude asked why Gus wasn't around, Zach told him it was because Gus did drugs. Not long after, Harley took the kids and left Springfield hoping Gus would get his act together while they were gone. About a month later, Harley and the kids returned and Harley was pleased to find that Gus cleaned up for good. On New Year's 2007, Zach wrote a paper for his Social Studies class which encouraged others to "Find your Light" by doing good deeds--theorizing that people were happy when they were being nice. At the same time, Zach suggested to his grandfather one night that they give a poor homeless woman a meal. That one act of kindness created a domino effect of good deeds throughout the city which culminated in a wealthy millionaire leaving a bagful of money on Main Street encouraging the people of Springfield to "Find Your Light".

A few months later, Zach's teenaged sister, Daisy, came home to stay with the family. Zach immediately was impressed with his big sister who he felt was "cool". Noticing friction between Harley and Daisy, Zach suggested to Daisy that a slushy might cheer her up. Daisy agreed and, despite not having a driver's license, she offered to drive Zach into town to get one. Though Zach suggested telling Harley where they were going, Daisy thought sneaking off would be more fun. Unfortunately, they had a minor accident. Though no one was hurt, a furious Harley blasted Daisy for putting her little brother's life in danger. Months later, Zach's family got a little bigger with the arrival of Rafe Rivera—the teenage son Gus never knew he had. Zach unknowingly caused some friction when he found and played with a syringe he found in Rafe's bag. Harley was certain that meant the boy was a drug user but Rafe informed his father that it was used for insulin for his diabetes. Unfortunately the Aitoro marriage seemed unable to withstand the arrival of Daisy's father, as well as Rafe and his mother, and Gus moved out before that fall.

Meanwhile, months later, Zach received a phone call from none other than Phillip! They had a quick chat and Zach promised not to tell Harley his father called. In addition, Zach tried to hide the new sneakers that Phillip had sent to him. Unfortunately, his mother found them and demanded to know where they came from. Zach was forced to admit that they were from his father and told Harley that Phillip would be at his ballgame. Meanwhile, Gus assured Zach and Jude that he would be a part of their lives no matter what and by the end of the year, Gus and Harley divorced.

In 2008, a new man entered Harley's life and home--Cyrus Foley. In addition to adjusting to this new man, Zach and Jude had to adjust to a change in living conditions. Harley had quit the police force and money became extremely tight when she took out a second mortgage on her house. In fact, money was so tight that for weeks, dinners consisted of noodle soup. As if all this change wasn't enough, the boys were saddened to learn that Gus died in an accident. In honor of their beloved stepfather, the boys created a memory book filled with pictures and stories about Gus to give to Rafe since he hadn't known Gus as long as they had. A few months later, Harley unexpectedly left town, leaving her kids in Buzz and Frank's hands. Weeks later, Harley asked Buzz to bring Zach to her and told Buzz that they would be gone the rest of the summer. A few months later, Harley shocked her father and Daisy by announcing that she would be staying in Greece. She also got Rick's permission to let Jude live with her abroad. Although she didn't say so directly, Buzz had the feeling that there was a man involved.