Chili's is using a heritage vibe in a new campaign that reminds people -- or even lets them know for the first time -- how the major chain was started by "hamburger hippies."

The restaurant's big push, which begins Tuesday, comes as Chili's takes a number of steps to try to reverse its sales declines amid a slump in the broader casual dining category it helped create.

Chili's plans to increase its marketing spending by 16% this fiscal year after cutting spending by 7% in fiscal 2016, which ended on June 29.

The campaign includes a new tagline, "Chilin' Since '75'," as Chili's highlights its history and moves away from the often-used food close-up shots seen for the past couple of years in its "Fresh is Happening Now" campaign. Both efforts are from longtime agency Hill Holliday.

"Over time the category advertising, casual dining advertising in particular, started to blend and look very similar," said Chili's SVP-Chief Marketing Officer Krista Gibson. "Lots of shots of fresh ingredients and lots of shots of food. We just felt like our creative and our campaign wasn't breaking through."

Now, Chili's is revisiting the '70s as it tells a part of the chain's origin story and mixes in current details, including a smaller dose of shots of new burgers and other fare.

"We were started by hippies -- hamburger hippies," Ms. Gibson said.

The first three commercials in the campaign use songs from the 1970s, a nod to Chili's start in Dallas in 1975: "Slow Ride" by Foghat, "Ooh La La" by The Faces, and "Tush" by ZZ Top. The chain will also start playing mostly '70s music in its restaurants, rather than a mix heavy with pop and current hits, to continue the feel of the campaign.

The idea continues in another more current way, as Chili's makes its debut on Snapchat with retro-themed filters.

"Chili's actually was started by a couple of guys and some authenticity is never a bad thing in this increasingly manufactured world that we live in," said Hill Holliday Chief Creative Officer Lance Jensen. "We wanted it to feel like it's true but it's also not trying so hard."

In planning for the new campaign, Ms. Gibson said Doug Brooks, who joined Chili's in 1978 and went on to become Chairman, President and CEO of Chili's parent company Brinker International Restaurants, met with people at the company and agency to share stories, details and pictures that helped inspire the work.

Along with the new TV spots, digital and social marketing, Chili's is making menu changes such as adding grass-fed beef burger patties as a premium option for $1. One of two new burgers on the menu is the Sunrise burger, topped with a cage-free egg.

Still, the company knows it needs to have a strong value play, especially with quick-serve chains touting deals at $3, $4 and $5 and its locations in oil markets hurting as that industry has been hit, executives said in early June. Other plans include joining the Plenti loyalty program.

Chili's ad spending declined 4.9% to $113.3 million in 2015, making it the 146th biggest advertiser in the nation, based on Ad Age Datacenter analysis of measured-media data from WPP's Kantar Media.

Brinker promoted Kelli Valade to the role of Chili's president in late June.

Hill Holliday is the creative and media agency on the campaign, with 360i Atlanta on digital and The Marketing Arm in Dallas on social.