NFL League or National Football League is a professional American Football League. It consists of 32 teams. National Football League is divided between National Football Conference (NFC) and the American Football Conference (AFC). Being one of the major professional sports league in the United States, particularly in North America, National Football League is a 17 week regular season that begins the week after Labor Day and goes on until the week after Christmas
Since its inception in 1920, National Football League has gone through a number of changes. Their uniform and Jerseys too have evolved with time.
Here is a brief timeline that depicts the evolution NFL uniforms and jerseys

1920
With its inception, NFL brought with itself some prized franchises.

1930
Many more NFL franchises came into the picture in the early decade. Wearing helmets were made mandatory during the 1930’s. Jerseys were still made of thick material and usually involved the use of basic colors.

1940
1940 was the time of the first helmet design when an NFL player from Los Angeles Rams painted Ram horns on his helmet. This led to franchises personalizing their teams with modifications. Many teams started switching colors, trying to find out the right color combination.

1950
By this year, NFL teams started to gain a sense of style and this brought never before seen variations in their Jerseys.

1960
1960’s marked the birth of modern day uniform. New teams came up with even interesting Jersey designs.

1970
The style and color of 1970’s started showing off on the NFL fields. It gave birth to the most uncommon color combination of NFL jerseys.

1980
The current jersey designs that we see were actually finalized in the 1980’s.

1990
With the designs getting finalized in 1980’s, 1990’s saw the beginning of the jersey boom. Jersey sales became one of the largest markets in the football merchandize.

2000
The millennium marked the birth of some new expansions. This gave rise to many more jersey changes. Throwback uniforms (from the past decades) became a tradition on Thanksgiving Day games.