Development
Comments about regional characteristics date back as far as the 12th century.
The American Dialect Society was formed in 1889 and a publication Dialect Notes was started. Dialect Notes was later renamed Publications of the American Dialect Society.
Articles:
The English Language: An Owner's Manual - Lee Thomas and Stephen Tchudi
The Study of Dialect: An Introduction to Dialectology - Keith Malcolm Petyt
What Can Be Done?
◊ Do not be resistant to change.
◊ Apply the "When Index" - When are these developments taking place?
◊ Recognize change is subtle.