Answer by taking a quote from the following article:

Clara Ann Fowler was born on November 8, 1927, in Claremore, Oklahoma (although some sources give Muskogee) into a large and poor family. Her father, B.A. Fowler, worked on the MKT railroad, while her mother, Margaret, and older sisters picked cotton. As she recalled on television many years later, the family lived without electricity, and therefore she could not read after dark. She was raised in Foraker, Hardy, Muskogee and Avant, Oklahoma, before attending Daniel Webster High School in Tulsa, from which she graduated in 1945.

Patti Page recorded several songs with Al Clauser & His Oklahoma Outlaws (1946), The Eddie Getz Orchestra, and the George Barnes Trio (1947). Page recorded her first hit single, "Confess", in 1947. Because of a strike, background singers were not available to provide harmony vocals for the song, so Page and the label decided to overdub the harmony parts. Bill Putnam, an engineer for Mercury Records, was able to overdub Page's voice, using the latest recording technology. Thus, Page became the first pop artist to harmonize her own vocals on a recording. This technique would later be used on Page's biggest hit singles in the 1950s. In 1948, "Confess" became a Top 15 hit on Billboard magazine, peaking at No. 12 on the "Best-Sellers" chart, becoming her first hit. Page followed the single with four more in 1948-1949, only one of which was a Top 20 hit, "So in Love" (1949). Page also had a Top 15 hit on the Billboard magazine country chart in 1949 with "Money, Marbles, and Chalk". In 1950, Page had her first million-selling single "With My Eyes Wide Open, I'm Dreaming", another song where she harmonized her vocals. Because she was overdubbing her vocals, Page's name had to be listed on the recording credits as a group. According to one early-1950s' chart, Page was credited as "The Patti Page Quartet." In mid-1950, Page's single, "All My Love (Bolero)" peaked at No. 1 on Billboard magazine, becoming her first No. 1 hit, spending five weeks there. That same year, she also had her first Top 10 hit with "I Don't Care if the Sun Don't Shine", as well as the Top 25 single, "Back in Your Own Backyard".

What happened afterwards?
This technique would later be used on Page's biggest hit singles in the 1950s.