Who invented or developed smart growth?  There are alot of
organizations out there that promote it, but I can't seem to find who
coined the term or who made the growth management concept so popular
for future developments?

Hello plland and thank you for your question.

Former Maryland Governor Parris Glendening is generally credited with
coining the term and concept of "smart growth"

"A national leader in the anti-sprawl movement, Glendening promotes
the development of model "Smart" Building Codes and mass transit
solutions in large cities. Credited with coining the term "smart
growth,"
http://www.southface.org/web/about_southface/media_room/press%20release%20archive/greenprints-press/pr-g2k3-glendenning.htm

"Maryland Gov. Parris Glendening, who coined the term "smart growth;"
http://www.sprawlwatch.org/calendar.html

"Smart Growth" is a phrase that's come to be associated with downtown
revitalization in many cities across the country. The man who coined
the term "Smart Growth" in 1996, during his first term as the governor
of Maryland, visited New Mexico this week to help planners and
builders decide what growth in New Mexico should look like. Parris
Glendening spent his eight years as governor of Maryland defining and
promoting Smart Growth strategies for that state."
http://64.233.167.104/search?q=cache:4Kf8WqR8v38J:kunm.org/news/archives/%3Fid%3DEplllpEkpyLmmBaHSb++%22term+OR+phrase+smart+growth%22+Parris+&hl=en

Thank you for your question, and if you need any clarification of my
answer, do not hesitate to ask prior to rating my answer.

Very best regards

THX1138

Search strategy included:
"term OR phrase smart growth" Parris 
://www.google.com/search?q=+%22term+OR+phrase+smart+growth%22+Parris+&hl=en&lr=&safe=off&as_qdr=all&start=0&sa=N