Site Environment
Project Objectives


On April 1, 1864, the sidewheel steamer Maple Leaf struck a Confederate torpedo in the Saint Johns River and sank. Launched at Kingston, Ontario, in 1851, Maple Leaf steamed on the lakes for eleven years. Most of that time her home port was Rochester, New York where she was critically important to the economic welfare of the city's commercial trade. In 1862 the Maple Leaf was sold to American investors and leased to the Union Army for use as a transport on the east coast. Her service paralleled that of many civilian vessels leased by the military during the conflict. The Maple Leaf's sinking killed four crew members and sent the personal effects of three Union regiments to the bottom. The cargo of personal effects did not impact the Union war effort and the strong Confederate presence along the river made salvage operations dangerous. The ship and cargo were never recovered.

In the early 1980's a group of Jacksonville, Florida residents interested in recovering Civil War artifacts began to search for the Maple Leaf. They found the ship in 1984 but legal ownership of the wreck remained a question. The group formed a corporation, St. Johns Archaeological Expeditions, Inc. (SJAEI), to act as the legal entity in a planned attempt to win ownership of the vessel in Admiralty Court.

The Maple Leaf was a civilian vessel leased to the federal government during the war. After the ship sank, the vessel's owners were compensated for its loss under terms of the lease agreement. This compensation gave title of the wreck to the Federal government. The government defended their claim of ownership in Admiralty Court with the Department of the Army acting as the government agent. The matter was resolved in an out of court settlement between SJAEI and the United States Government 1986. While the government retained ownership through the agency of the Army, SJAEI received exclusive salvage rights. Recovered artifacts would be split, with SJAEI receiving eighty percent and the federal government twenty percent. The State of Florida would receive half of the government share in return for any services given to the project (St. Johns Archaeological Expeditions v. Maple Leaf and the United States of America, 1986).

SJAEI conducted excavations in the aft cargo hold during 1988 and 1989. Their objective was to find material to conclusively prove the vessel's identity. This work generated enormous interest and enthusiastic support from the public as well as a small amount of grant money from the City of Jacksonville. It also joined public and private sector interests into a continuing cooperative scientific archaeological investigation.

During the late 1980's and early 1990's, acceptance of the Maple Leaf as a legitimate archaeological project by the professional archaeological community came slowly and funding was scarce or nonexistent. Finally, in 1990, the Florida Department of State, Division of Historical Resources provided a Special Category Grant through the Jacksonville Museum of Science and History to fund research and the production of educational materials. The Jacksonville Historical Society became the sponsoring institution for a second grant awarded in 1991. With adequate funding secured, SJAEI sought professional assistance from the Program in Maritime History and Nautical Archaeology at East Carolina University to continue the research. State grants were awarded in 1992 and 1993 which allowed continued additional study.


The Maple Leaf is located in Section 26, Township 4S, Range 26E, Duval County, Florida. It sank at a prominent bend in the St Johns River off Mandarin Point, 11.2 miles (18 kilometers) upstream from Jacksonville, Florida. The hull lies in the navigation channel, 2550 feet (777 meters) from the eastern shore, perpendicular to stream flow with the bow pointing to the east. Water depth is 21 feet at high tide (Figure 1).


The physical terrain of northeast Florida consists of lagoons, estuaries, lakes, rivers, coastal dune ridges, relict sand dunes, marine terraces, and barrier islands. These features tend to be oriented on a north/south axis paralleling the coastline. The sloughs and valleys separating higher areas are poorly drained and many have wetlands and surface drainage channels.

The St. Johns River occupies a lagoonal valley formed as a result of fluctuating sea levels during Pleistocene glaciation. The valley began as a lagoon behind a long barrier island during a time of higher sea levels associated with the interglacial periods. As sea level dropped, the St. Johns River formed in the shallow stranded valley. The Fig 1 large lakes characterizing the present river formed in depressions of the lagoon (Clewell 1991:19).

Site Environment

The St. Johns River, the longest river in Florida, is unusual in North America for its northward flow. Its headwaters lie in the marshes of St. Lucie and Indian River Counties. It flows 480 kilometers north along the Atlantic coast dropping only eight meters along the way (DeMort 1991:97-99). The river's original water source is Florida's abundant rain fall which replenishes the headwater marshes, collects as a surface flow, and drains into the river or one of its tributary streams. The surface flow leaches tannin from decaying vegetation accumulated in the marsh imparting a dark reddish-brown hue to the water. This color is the defining characteristic that makes the St Johns a blackwater river. Tannic water is often nutrient-poor, low in dissolved oxygen, and strongly acidic (Clewell 1991:23). These factors are moderated at the site area by tidal influences.

Due to the river's low vertical drop, the tidal reach extends over 59% of the total length. The astronomical tides affecting Florida's Atlantic coast are semidiurnal with two highs and two lows per tidal day. Flow reversal occurs with each change and is influenced by wind, water density, freshwater inflow and channel configuration (McPherson and Hammett 1991:32-35). These factors also affect current strength at the site location. The measured and estimated strength under the astronomical phase corresponding to mean tidal conditions is 1.4 feet/second (.83 knots/hour)(Bodge 1987:6-7). The highest tides, and subsequently the strongest currents, occur during full and new moon phases. These maximum current velocities have not been measured.

In the St. Johns' tidal area, vertical stratification is often present due to density differences between sea water and freshwater. A dense saltwater wedge flows upstream along the bottom with the tide, mixing with the fresh river water above. The rate and amount of mixing is dependent on wind and freshwater inflow. This often creates a broad transition zone from fresh to salt water (McPherson and Hammett 1991:37). Wind is an important factor on the broad stretches of the St. Johns where the open fetch can extend several miles.

At high tide the St. Johns River is 21 feet deep at the Maple Leaf site and the intact main deck is covered by 4 to 8 feet of sediment. Only a few structural features protrude above the river bottom to mark the site (Figure 2). The largest visible component is the north-south oriented paddle wheel shaft that identifies the amidships area. To the west, the rudder post marks the stern and confirms the east-west orientation of the vessel. This alignment is consistent with historical accounts of the loss (Murray 1864). Originally, no structural features marked the bow, but diver activity has exposed the stem and pawl post.

The Maple Leaf site area is a marine estuary and strongly influenced by ocean tides. Brackish water is normally present at the site location with salinity ranging from 1.0 parts/thousand at low tide to 5.0 parts/thousand at high tide in the Orange Park/Mandarin area (DeMort 1991:105). Salinity directly affects the shipwreck through chemical processes occurring on exposed structures and by dictating the type of marine Fig 2 organisms able to exist in the estuarine environment. Of particular concern are the corrosion of the iron paddle wheel shaft and ship worm damage evident on the bow rail now on display at the Jacksonville Museum of Science and History.

The river bottom surrounding the site area is a flat featureless plain of gelatinous, highly organic sediment. The sediments consist of sand, colloidal silt, clay, and organic matter. The top stratum is a soft mud described as fluff (Duncan 1994:126). A sample of the material contains 25% sand size particles and 75% silt and clay size particles (Bodge 1987:12).

Flocculation is the main cause of sediment deposition at the Maple Leaf site. Clay, silt, and organic matter are the primary components. Organic matter is supplied by plant detritus from the surrounding basin and from riverine plant and animal organisms. Clay and silt come from weathering and runoff. Flocculation increases in warmer months as temperature increases and the water becomes less viscous. Lower water viscosity elevates the rate of fine particle deposition (Duncan 1994:127-128).

Prior to deposition, the river carries the organic matter and colloidal clay and silt as a suspended load, largely along the river bottom (Duncan 1994:127). In the summer there is a noticeable suspended layer on the bottom, twelve to eighteen inches thick. The layer flows across the bottom with changing tidal currents. The suspended material settles out when the water is trapped in a depression such as the large excavation units on the site. This situation causes constant and immediate refilling of excavation units. In addition, man-made debris carried along the bottom also settles into these depressions.

Visibility in the water column is dependent on dissolved tannin and suspended load, while rain, wind and tidal flow have strong contributing impacts. Natural light penetration can exceed 15 feet under ideal conditions but normally fails about 10 feet below the surface. Artificial light penetration is dependent on diver activity and suspended silt. It can range from zero to 5 feet. In the suspended layer on the bottom, visibility is totally obscured and the problem is compounded when sediments are disturbed. As a result, all excavation work on the site is hampered by zero visibility unless the suspended silt layer is diverted from the area.

Project Objectives

The Maple Leaf contains a unique legacy from the past, important as a resource for Civil War history and maritime heritage. The National Park Service designated the site a National Historic Landmark in the fall of 1994. The cargo contains a material record of the American Civil War and those who fought in it. Systematic archaeological investigation of the well preserved cargo is currently revealing aspects of the conflict that do not survive in written form. The vessel carried the personal belongings and camp equipment of three Union regiments, sutler stores, and the headquarters equipment of General Robert Foster. Since many artifacts can be traced to their original owners, the collection offers insight on historical, sociological, anthropological, and material culture questions regarding the Civil War and the mid-nineteenth century. The Maple Leaf's undisturbed archaeological context will provide the first opportunity to study a large Civil War collection with archaeological and historical integrity.

The second major element of the site is the ship itself. This thesis will concentrate on an analysis and interpretation of the hull and propulsion system. The surviving structural and mechanical remains of the Maple Leaf represent marine technology and commercial interest on the Great Lakes during the mid-nineteenth century. The hull can provide information on marine architecture, engineering, construction techniques, and internal arrangements including cabin space and cargo stowage methods. It represents the typical vessel type that carried a major share of passenger traffic and package freight on the Great Lakes.

Archaeological investigations of the ship took place over three summers. The field research included an examination of the existing vessel remains and excavations in the forward and aft cargo spaces. The purpose was to collect diagnostic data on the ship and create a baseline study to help guide future research plans.

Specifically related to the ship, the investigation sought to determined what parts of the vessel still exist and their structural integrity. Historical documentation and several preliminary dives indicated nothing remained above the main deck. After considering the ship's bi-lateral longitudinal symmetry, excavation was confined to the starboard side. Working on the starboard side also offered the chance to examine possible torpedo damage reported near the starboard bow (Johnson 1864).

The project research design divided the main deck excavation into three areas to be completed over three years. During the first year, 1992, the forward deck was excavated from the bow to the engineering spaces. In 1993 the engineering spaces were examined. The final year, 1994, the aft deck from the engineering spaces to the stern was investigated. The research design also called for developing and refining techniques to work on the low visibility site (Cantelas 1992; Van Tilberg 1994).

The two primary elements of the ship are the wooden hull and its propulsion system. Several important hull elements will be examined including basic diagnostic construction features, the deck layout, deck furniture, space utilization, and the longitudinal reinforcing system used to prevent hogging. Although the propulsion system is badly damaged, remaining elements include the boilers, power plant, walking beam, paddle shaft and paddle wheel construction.