The proposal for the Water Management District to buy the land, located in Palm Beach, Hendry and Glades and Gilchrist Counties, was announced by Governor Charlie Crist and company executives this week.
The land and assets include sugar cane land, the sugar mill, refinery, citrus plant, citrus nursery, rock mines, railroad and railcars, and equipment.
The Everglades are a subtropical wetland in southern Florida, home to a vast array of flora and fauna including alligators, mangroves and pine forests.
For decades they were regarded as unutilized marshland that had the potential to be farmed, and thus contribute to the local and national economy.
However this has had a severe impact on the ecology of the region.
A $8bn restoration program for the Everglades was announced in 2000, but has not been completed because of funding problems, according to environmentalists.
In particular, environmentalists have striven for the restoration of a 99 mile long shallow river from the freshwater Lake Okeechobee to Florida Bay, known as the 'River of Grass'.
Many have said the plan was never possible without US Sugar handing over the land, however; indeed, some campaigners have battled long for the land to handed back to the wilderness.
US Sugar said in a statement that the agreement in principle has been a "bittersweet moment " for the company, which has farmed the land for four generations.
Its main activities are in sugar and citrus farming.
"However, we believe the cause is good, and US Sugar is proud to be part of this historic opportunity to make extraordinary progress in Everglades restoration and restore much of the natural footprint of South Florida."
The proposal still gives US Sugar the right to farm the land for a transitional period over the next six years, so the effect on the Everglades and on the business will not be immediate.
The company said this will allow it to "fulfil its long term business obligations" , as well as give its 1700 employees time to seek out new opportunities for their livelihoods and lifestyles.
State agencies have been asked to create a special initiative to create new jobs in the region.
For the Everglades, it will take a decade to build the reservoirs that will reinvigorate the water supply from Lake Okeechobee.
In addition, the details of the plan still need to be worked out.
State officials still need to value the land and raise the funding, and negotiations are required with some other land owners in the area.
US Sugar and the industry US Sugar has said that the proposed deal appears to be at a fair price for shareholders.
CEO Robert Buker made it clear that the deal would not be on the table if the price were not right.
Buker also told a new conference that the decision to sell was not linked to company profits.
The company presently produces 700,000 tons of raw sugar annually, and boasts the newest sugar refinery in the United States.
Its orange groves cover 30,000 acres, and yield 120m gallons of juice a year.
This makes it the largest supplier of private label not-from-concentrate orange juice in the US, it claims.