These tariff hikes come at the "worst possible time", right in the middle of the busy holiday shipping period, the coalition wrote.
"The full adverse impact of these tariff increases will be felt entirely in the US and could represent one of the largest tax increases in American history," it was cited as saying by Xinhua news agency.
The letter was organized by Americans for Free Trade Coalition, which represents manufacturers, retailers, farmers and agribusinesses, technology companies, service suppliers, natural gas and oil companies, among others.
Despite the delay of some tariffs, a large portion of holiday merchandise will still be hit by September and October tariff increases "at an even higher rate than was initially anticipated", the coalition wrote.
"With some products facing tariffs as high as 30 per cent, many businesses will have no choice but to pass along those costs to consumers."
Noting that many of the industrial inputs are sourced in China, the coalition wrote that these new tariffs will act as a tax on US manufacturers and farmers.
"And because these tariffs were announced with little warning, it is impossible for US importers to share the burden with supply chain partners in China or shift their production to other countries," it said.
Subjecting American companies, the workers they employ and the consumers they serve to new and unprecedented taxes "takes us further away from the deal you are working to craft", the coalition wrote.
"Ordering companies to leave China, the world's second largest economy, is not a solution and is unrealistic," it added.
( With inputs from IANS )