Outlined below are some significant changes in Connecticut's history of regional planning. In no way is this meant to be comprehensive.
None of the changes noted below happened in a void. There were forces (and opposing forces at times) on local, state, national and international levels that impacted regional planning in Connecticut. Such as: war; post-war transitions; housing; industrial growth; conservation and land use; civil rights; urban/rural studies; education; economics, etc. Sometimes administration of a program required regional agency involvement (ex. Federal Housing Act of 1954, Sec. 701 grants). This guide will focus on Connecticut and touch on other forces only if the impact was notable.
Please keep in mind, these are approximate time periods. Some sources may have used calendar years, some sources may have used fiscal years.
The first part of this decade saw work on planning and implementing a regional planning program with fewer logical planning regions and corresponding Regional Planning Organizations (RPOs). By January 1, 2015, Connecticut had brought the 15 regions down to nine, with all RPOs being Regional Councils of Governments (RCOGs or COGs). Since then, there has been legislation dealing with various aspects of regional planning (programs, funding, incentives, COG authority, etc.). A few examples have been included below - see the Connecticut General Statutes for further research.
This decade saw a growing interest, on national, state, and local levels, to expand planning and working with a regional focus.
"There are two major reasons: recognition that land use planning needs to occur in a more methodical and integrated manner in order to preserve the character of the state and reduce sprawl; and a realization that service sharing arrangements can achieve cost savings."[1, p.II]. Nationally there has been a growing interest in "Smart Growth", which is similar to the concept of "responsible growth" in Connecticut[3, pp.2-3]. This decade saw the first formal changes in the geographic boundaries of the logical planning regions since the 1970s.
The early 1980s focused on studying the statutory authority and effectiveness of the State's Regional Planning Agencies. One Regional Planning Organization (RPO) ceased operations, leaving 15 geographic planning regions and 14 RPOs and questions regarding the region without an RPO, including fiscal concerns.
Nationally, the economic philosophy of the "New Federalism" impacted programs on most levels of government. "The Reagan Administration's FY 82 budget eliminated the HUD '701' planning program and the funds which, for several years, had been the keystone of regional agency funding..." [6, p.22] Since the early days of regional planning in Connecticut, a key incentive to join an RPO was federal funding's requirement that applications go through a regional agency."[6, p.22] During the peak years of federal support -- the 1960s and 1970s -- Connecticut's RPAs had received 70% of their financial backing from federal program sources, primarily '701' planning assistance...". [15, p.4] The state statutes did not address how RPOs would assess the member towns; individual plans were devised by the organizations. 
During the 1990s there was a focus on streamlining state government and delivery of services. The Thomas Commission (SA 89-40) was to conduct a comprehensive study of state government organization in 1990. Implementation of recommendations impacted RPOs. Several Public and Special Acts in the early 1990s addressed streamlining state government. The Office of Policy and Management (OPM) was called to study and prepare a report on forming uniform regions across Connecticut for all state agencies. The uniform regions were not implemented.
Several Public Acts addressed different aspects of the State Conservation and Development (C&D) plans. The legislation had requirements for local and regional C&D plans. The Regional Economic Development Act (PA 93-382) stated it was "To provide for revitalization of the state's economy."
"Regional planning in Connecticut received its greatest impetus during the 1960s and 1970s under federal requirements that designated agencies be 'in place' as conduits for funds and programs dealing with issues such as environmental protection, air quality, transportation, water quality, etc."[15, p.i] Regional planning organizations grew during this time as they addressed national trends such as: "environmental protection, air quality, mass transportation, energy consumption and others..." and the federal government recognized regional planning organizations as the means to address the issues and through which to pass federal monies.[1, p.4]
During the 1970s The Federal Government, through the Office of Management and Budget (OMB), required towns to submit federal grant applications through a local Regional Planning Organization (RPO) for comment before it went to Washington, DC. This lasted until 1982.
1940s and 1950s saw rapid growth in Connecticut - in population, housing, motor vehicles, jobs, and such.[3, p.8]
"The planning law of Connecticut dates from 1918 and the zoning law from 1925, but the regional planning law aimed at bringing together representatives of neighboring communities to work out larger area problems starts with 1947."
By 1946, many states were authorizing state and local planning and/or zoning agencies according to a survey conducted by the Connecticut Development Commission (CDC). The CDC was calling for both zoning and planning legislation to be re-written, as well as calling for regional planning studies to become the first step in any zoning and/or planning on the local level in such a small state. In the interim report to Gov. Baldwin, the economic savings for technical advice was already being highlighted. "By 1947, state law began requiring towns with planning commissions to adopt municipal plans of development."[3, p.7]
1950s - Events during this decade provided the impetus needed to start to move Connecticut's regional planning forward. The Federal Housing Act of 1954 required grant applications to go through regional planning agencies within states. "Connecticut's response, in 1955, was to authorize the Connecticut Development Commission to divide the state into such logical regions."[6, p.3] The process of defining the regions took into account many different factors (a few being: population; news and media usage; development trends; commuting patterns; phone service; parcel delivery, and more). "The process of definition [took] many years, with some final determinations being made as late as the 1970's.".
Connecticut experienced severe flooding in 1955 and 1956. In response, regional studies of major watersheds and flood valleys were conducted. "These studies became in essence comprehensive regional plans for the areas and further pointed the way to organized regional planning in Connecticut."[17, p.2] The previous regional planning enabling legislation was amended by the Connecticut General Assembly (CGA). Along with the Connecticut Development Commission's duty to define "logical regions", many in-depth studies came out of this legislation. Over time, the defining boundaries experienced some minor adjustments.
The Connecticut State Development Commission was established. Economic development was the chief emphasis, but over time planning received increased attention.
Connecticut has a long, and strong, tradition of local control. This had a foundation in England, before they settled in what was to become the United States.