The first broadcast of "I Love Lucy" hit television screens on October 15, 1951, with the episode "The Girls Want to Go to a Nightclub". This was not the first episode filmed, but due to pre-production issues, this was the first episode to air. The first to be filmed (and what I still consider the very first "I Love Lucy" episode) was "Lucy Thinks Ricky is Trying to Murder Her", which was filmed on September 8, 1951.
Throughout the pilot and first episode, Lucy was costumed in large robes and pajamas, first to conceal her pregnancy, then to hide her bandages and healing from her Caesarean section. She had given birth to Lucie Arnaz on July 17, 1951, taken a brief break, and returned to work to film the first episodes.
The show was not an instant success, but became increasingly popular about halfway through the first season. At this time, there were relatively few televisions in the US, but it did not take long for "I Love Lucy" to become one of the staples of American life. Not long after the show debuted in it's regular time slot (Monday nights at 9:00pm), it was observed that activity across the country was affected. Traffic was drastically reduced, restaurants saw less customers, and even retail shops noticed a drop in business. As the show progressed, the actors got to know their characters as well as the writers did, the technicians mastered the camera, editing, and recording techniques, and "I Love Lucy" was well on it's way to becoming a television legend.