What were Samuel Johnson's goals for and what did Dictionary of the English Language do for the English language; what did it accomplish?Please...

According to href="http://andromeda.rutgers.edu/~jlynch/Johnson/Guide/dict.html">Jack Lynch,
Ph.D., of Rutgers University, Samuel Johnson's Dictionary of the
English Language (London, 1775) was the standard English dictionary for one
hundred and fifty years, surpassed only by the Oxford English
Dictionary (OED) at the beginning of the twentieth century; the OED's first
fascicle (Volume A-B) was published in 1884. Therefore one of
Johnson's Dictionary's contributions to the English language was to
provide the first definitive authoritative source for English language lexicographical
reference.

Johnson's was not the first dictionary of the
English language but it was the first great dictionary of the English language. The
fourth paragraph of Johnson's href="http://ethnicity.rutgers.edu/~jlynch/Texts/preface.html">Preface to
the First Edition tells part of Johnson's goal and likewise part of what Johnson's
Dictionary contributed to the English
language:

readability="15">

When I took the first survey of my undertaking,
I found our speech copious without order, and energetick without rules: wherever I
turned my view, there was perplexity to be disentangled, and confusion to be regulated;
choice was to be made out of boundless variety, without any established principle of
selection; adulterations were to be detected, without a settled test of purity; and
modes of expression to be rejected or received, without the suffrages of any writers of
classical reputation or acknowledged
authority.

Since Johnson's
work on the Dictionary was almost single-handed, London was the
focus of his efforts. The above paragraph of his Preface tells us that, though the
London dialect of English had long been the prestige dialect and the dialect of
literature and government, there was not a codified standardization of English so
varieties of pronunciations, usages, spellings, and rules of language order (called
grammar) were widespread and numerous. Therefore a second contribution was that
Johnson's undertaking distilled some order and standardization upon the variety still
prevalent in the preferred prestige London dialect of the English language in the latter
part of the eighteenth century.

According to title="Samuel Johnson (1709-1784) - Byname Dr. Johnson. Petri Liukkonen on
http://Kirjasto.sci.fi/" href="http://kirjasto.sci.fi/samuelj.htm">Petri
Liukkonen, Johnson followed the models of French and Italian dictionaries and
chose to illustrate his 40,000 definitions with about 114,000 quotes from literature and
every other academic field, thus addressing one of the concerns he expressed in his
Preface: "[words were] without the suffrages of any writers of classical reputation or
acknowledged authority." When the OED was later being complied by Dr. James Murray, who
began the work, Johnson's formulation of illustrating with quotations was carried on, in
fact, OED uses the earliest known quote for each usage. Therefore another contribution
of Johnson's Dictionary was to have begun the chronicling of the
usages and meanings along with changes in usage and meaning in the English
language.