1941 – An entry limit of 2,500 dogs is established. Entries are restricted to dogs that have won a first, second or third prize (except puppies) at an AKC Show.
1948 – A blue ribbon, won at an AKC or Canadian Kennel Club (CKC) show, is now required to qualify to enter Westminster. The Novice Class is dropped.
1950 – Entries for Exhibition Only are dropped.
1958 – The 6-9 month puppy classes are dropped.
1960 – The 9-12 month puppy classes are dropped.
1961 – Team (four dogs together) competition is discontinued.
1964 – Miscellaneous Class is dropped. A CKC win no longer counts for qualifying for Westminster.
1967 – Entries are now required to have won at least one point.
1969 – Entries are now required to have at least one major win (3 points at a single show).
1970 – Entry limit is raised to 3,000 dogs.
1970 – One-day benching begins, with three groups to be judged each day.
1972 – Brace competition (two dogs together) is discontinued.
1982 – Entry limit is reduced to 2,500 dogs.
1992 – Entries are restricted to AKC champions of record.
2000 – Invitations to “pre-enter” are sent to the top five dogs or bitches in each breed or variety. After “pre-entries” close, other entries are accepted in a normal manner until the show limit is reached.
2012 – Due to the renovation of Madison Square Garden, the entry limit is reduced to 2,000 dogs.
2013 – Westminster moves the breed judging during the day to Piers 92/94 in New York and increases the entry limit to 3,200 dogs. In addition, for the first time since 1991, non-AKC champions will be eligible to enter and compete in the classes (Bred By Exhibitor, American Bred and Open). To be eligible for these classes, dogs must have won at least one major award (3 points or more from the classes at one show). As has been the case since 2000, the top five dogs in each breed in breed point standings will be invited to pre-enter. In addition, Best of Breed winners of National Breed Club specialties in the previous calendar year
will also be invited to pre-enter.
2014 – Entry limit reduced to 3,000 dogs.
2015 – Entry limit reduced to 2,800 dogs.
2020 - Due to the closing of Pier 92, the show was held over three days on Pier 94. The entry limit was reduced to 2,500 dogs and was a "Champions only" event.