The only state that doesn't have a national park wants one

— -- Delaware is known by several nicknames — the First State, the Diamond State, the Blue Hen state, a tax-free shopping state — but a frustrated U.S. senator imagines an additional sign at the border.

"Welcome to Delaware — the only state without a national park," jokes U.S. Sen. Tom Carper of Delaware.

Carper, a Democrat, has been pressing Congress for about a decade to create a national park in Delaware. All 49 other states — as well as Puerto Rico, Guam, the U.S. Virgin Islands, Northern Mariana Islands and American Samoa— have units of the National Park Service.

Carper's latest proposal would link six historic sites in the state to tell the story of Dutch and Swedish settlements in the 1600s and Delaware's role as the first state to ratify the Constitution in 1787. He says the Senate probably will vote on his proposal this year.

Opponents have balked at any proposal to add to the national park system, which faces a $7 billion to $9 billion backlog of maintenance projects at its nearly 400 existing parks. Carper says his proposal would be budget-neutral.

It would be fitting for Delaware to get a national park in time for next year's 375th anniversary of the arrival of Swedish settlers in the state, says Rebecca Wilson, executive director of Old Swedes Foundation, which supports Holy Trinity (Old Swedes) Church in Wilmington, Del. It is one of the six sites in Carper's proposal.

In 1638, Swedish settlers established New Sweden at Fort Christina near the Delaware River south of Philadelphia. The fort is also part of Carper's proposal. In 1698-99, settlers built the church, which is the oldest active church in the USA still in its original location. "This site has been here for 314 years, and it's seen everything," Wilson says.

The settlement later became the city of Wilmington, but Fort Christina's exact location is unknown. A national park designation could allow for a search, Wilson says.

Carper's proposal also includes the Old New Castle Court House and Sheriff's House in New Castle, where the Delaware Assembly voted to end English rule on June 15, 1776; the plantation of John Dickinson, known as "Penman of the Revolution"; The Green in Dover, where Delaware ratified the Constitution; and the Ryves Holt House in Lewes, built about 1665.