INDEPENDENCE, MO. ? Backers of a plan to expand the federal Truman National Historic Landmark District say it would reflect the impact former president Harry S. Truman had on his city.

“We need to tell the whole Truman story in Independence,” said James Sanders, the outgoing superintendent of the Truman National Historic site.

Sanders, now superintendent of the Lincoln Home National Historic Site in Springfield, Ill., prepared the expansion plan. It is scheduled for submission later this month to the Department of the Interior.

The district, beginning at Truman’s suburban Kansas City home and running north, now includes about 100 buildings. The proposal would expand it to 620. Owners of those buildings could be eligible for state and federal tax credits, depending on how the buildings are used.

Independence Square, where state officials declined in the late 1990s to place some buildings on the National Register of Historic Places, would be included in the expansion. That would automatically put the square on the register.

City officials had pushed for the square’s inclusion, but the state believed that too many of its buildings had been changed or demolished to make the area truly historic.

But Sanders said a study, prepared as part of the expansion proposal, shows that more than half the buildings on the square relate to the 33rd president – and that number could grow as more owners restore their properties.

The federal government established the district in 1971, after Truman – who at first was reluctant to support it – gave his approval. He had objected that the district could be seen as an inappropriate personal tribute, but was persuaded by his son-in-law, Clifton Daniel, that it would aid in preservation.

Independence set up its own Truman heritage district in 1974, but reduced its size 10 years later to make way for a church expansion project – causing hard feelings on both sides of the preservation debate.