Since the dawn of the twentieth century, the governments of the United States and Canada had been negotiating for the joint development of the Great Lakes-St. Lawrence system to allow ocean vessels to sail up the St. Lawrence River from the Atlantic Ocean to the Great Lakes. At first the Canadians were reluctant to participate with the United States in such a project. It was, however, the United States Congress which proved to be the major stumbling block for the seaway project. Long after the Canadians had been won over to the plan, the American Congress continued to delay its approval. For over twenty years, Washington's powerful anti-seaway lobby, composed chiefly of railroad and coal interests, the East and Gulf Coast ports, and American maritime interests, were successful in stalling the project. However, the situation began to change after the Second World War. The experiences of this war and the Cold War which followed, had drawn the two countries closer together both militarily and economically. Moreover, the unparalleled expansion of the Canadian economy made it imperative for that country to develop the navigational and power potential of the St. Lawrence. Because of the increasing depletion of vital resources, especially iron ore, the United States had grown more and more dependent on Canada for such essential materials required by American consumer and defense industries. The St. Lawrence Seaway would assure the Midwestern industries of a constant cheap supply of these resources. This paper investigates the way in which the changing circumstances of the post-war years affected the decisions of the United States Congress on the St. Lawrence Seaway project. Drawing heavily from the Congressional investigations and debates, it tries to determine the situation in Congress, and especially in the Senate, the main battleground in the debate over the St. Lawrence Seaway. It tries to establish the significance of the Canadian ultimatum, and of the arguments of national defense and security, in changing the Congress' attitude on the project. Moreover, it looks at the various factors affecting the 1954 vote on the seaway. 1952 proved to be the turning point. Elections held in the United States that year brought a new Republican administration into Washington together with a Republican majority in Congress. In Canada patience had worn thin, and the prime minister issued an ultimatum to the Americans - either they join in the project shortly, or the Canadians would build it on their own. The impact of this ultimatum had all the more force because the post-war economic boom in Canada had made that country confident and capable of taking on the project alone. Truman's ready cooperation had, as well, helped to facilitate the joint development of the power project, a pre-requisite of the "all-Canadian" seaway. This ultimatum acted as a catalyst in achieving Congressional approval of American participation in the St. Lawrence Seaway. By making the old economic arguments irrelevant, it allowed the debate to be concentrated on the issue of national security. Together with the "Cold War" mentality prevalent in the United States at the time, it created a situation in which the new president, Dwight D. Eisenhower, could use his enormous influence as president, and his prestige as a military hero, to their fullest advantage in influencing Congress. Faced with the Canadian ultimatum and the need to have a voice in the control of the important waterway which would transport iron ore and other vital materials to American Midwestern industries, the Congress overcame its inertia and approved a limited seaway role for the United States. / Arts, Faculty of / History, Department of / Graduate

No description available.

No description available.

No description available.

Thesis--Catholic University of America. / Bibliography: p. 155-167.

Thesis--Catholic University of America. / Bibliography: p. 155-167.

No description available.

No description available.

The late Neogene represents an exceptionally dynamic period in Earth history during which the Northern Hemisphere has transitioned from a warmer, more equable climate to a cooler, more transient state characterized by waxing and waning continental ice sheets. While geographical distal, the tropical ocean has played a significant role in shaping the evolution of the climate system, as the opening and closing of low latitude (LL) ocean gateways and reorganization of oceanic and atmospheric circulation structure have helped shape the climate system into its present form. This study provides a reconstruction of sea surface temperature (SST), ocean circulation, and thermal structure of the LL eastern Pacific and North Atlantic based upon the compilation of proxy data derived from planktic foraminifer assemblages and geochemical techniques. This research begins with a paleoceanographic reconstruction of the eastern tropical Pacific (ETP) and subtropical Northwest Atlantic (NWA) during the early stages of uplift of the Central American Isthmus and associated shoaling of the Central American Seaway (CAS). In the subtropical NWA (DSDP 103 and ODP 1006), the 5.2 to 5.1 Ma interval is characterized by an increase in SST and sea surface salinity, indicating a strengthening of the Florida Current (FC) and Gulf Stream (GS). Sea surface temperature in the ETP Warm Pool (DSDP Site 84) remained relatively stable between 6.9 and 5.1 Ma, during which El Niño-like conditions persisted. A slight cooling is observed after this interval (with synchronous warming in the NWA), followed by the onset of major cooling at ~3.2 Ma, both of which are preceded by a shallowing of the thermocline. Stepwise cooling is attributed to enhanced Atlantic meridional overturn circulation (AMOC), which caused a shoaling of the main tropical thermocline, thereby strengthening the Walker Circulation and weakening the Pacific North Equatorial Counter Current. During the mid-Piacenzian warm period (MPWP; ~3.3-3.0 Ma), SST in the Panama Basin was ~0.8°C cooler than today, while the subtropical NWA was only ~1.1°C warmer. This corroborates evidence for reduced meridional SST gradients during the mid-Pliocene as well as the hypothesis that more vigorous ocean circulation--particularly in the NWA--was critical during this period. The timing of SST changes in the ETP and NWA (~5.1 Ma) suggest that the termination of permanent El Niño and enhanced AMOC did not contribute significantly to the onset of major Northern Hemisphere glaciation (NHG), as both of these events occur well before the beginning of the glacial cycles. However, these processes may have contributed to the development of the small ice sheets of the late Miocene and early Pliocene, but were most likely only preconditioning factors for the onset of major NHG. In contrast, changes in SST and relative thermocline position suggest that high latitude (HL) processes and global cooling may have influenced thermal structure in the ETP. The SST estimates provided indicate that even in its early stages, the shoaling of the CAS had significant implications for low-latitude ocean circulation and thermal structure, as well as for some of the most significant global climate events of the late Neogene, including the MPWP. During the MPWP, mean global surface temperatures were similar to those predicted for the next century (2-3˚ C warmer) while atmospheric CO2 concentrations, paleogeography, and paleobiology were similar to today. As such, the MPWP has been studied in detail as a potential (albeit imperfect) analog for future climate change and has provided a natural and unique test-bed for the integration of proxy data and general circulation models. Central to this research effort is the Pliocene Research, Interpretation, and Synoptic Mapping (PRISM) project, an iterative paleoenvironmental reconstruction of the MP focused on increasing our understanding of warm-period climate forcings, dynamics, and feedbacks by providing three-dimensional data sets for general circulation models. A mainstay of the PRISM project has been the development of a global sea surface temperature (SST) data set based primarily upon quantitative analyses of planktic foraminifer assemblages, supplemented with geochemical SST estimates wherever possible. In order to improve spatial coverage of the PRISM faunal and SST data sets in the LL North Atlantic, this study provides a description of the MP planktic foraminifer assemblage and multiproxy SST estimates from five Ocean Drilling Program sites (951, 958, 1006, 1062, and 1063) in the North Atlantic subtropical gyre (NASG), a region critical to Atlantic Ocean circulation and tropical heat advection. Assemblages from each core provide evidence for a temperature- and circulation-driven 5-10° northward displacement of MP faunal provinces, as well as regional shifts in planktic foraminifer populations linked to species ecology and interactions. General biogeographic trends also indicate that, relative to modern conditions, gyre circulation was stronger (particularly the Gulf Stream, North Atlantic Current, and North Equatorial Current) and meridionally broader. Overall, SST estimates suggest that surface waters in this region were not significantly warmer (1-2˚ C) than today and that mean annual SSTs along LL western boundary currents were indistinguishable from modern. Multiproxy SST data also provide evidence for enhanced northward transport of warm, salty, oligotrophic surface waters via a vigorous western boundary current system with warmer (cooler) cold-season (warm-season) temperatures. Collectively, this reconstruction of SST and ocean circulation provides support for a model of an enhanced Atlantic meridional overturn circulation (AMOC) system, with particularly vigorous LL western boundary currents and thus, more efficient northward heat transport. These trends therefore suggest that more vigorous thermohaline circulation, in conjunction with elevated atmospheric CO2 concentrations, played a significant role in shaping the global surface temperature distribution during the MPWP. A strengthening of the AMOC under warmer-than-modern conditions has significant implications for future climate change. The current generation of climate models suggests that HL warming and associated ice-sheet melting will induce a freshening of the North Atlantic and thus, to a reduction in the strength of the AMOC, thereby buffering surface temperature increases in the Northern Hemisphere. However, if after this transient period of climate system adjustment, Earth returns to a more Pliocene-like climate state the AMOC system may strengthen, thereby exacerbating the HL warmth caused by elevated atmospheric CO2 concentrations. Thus, through the reconstruction of warm-period SST and ocean circulation, this research provides insight into the potential operation of the LL North Atlantic and its associated impact on broad-scale Northern Hemisphere climate.

No description available.