August 24, 1975 Trenton Speedway, New Jersey State Fairgrounds, Hamilton, NJ: Aerosmith/Kingfish/Poco/others

Continued research into the touring history of Bob Weir and Kingfish has uncovered a hitherto forgotten outdoor concert in the Summer of 1975 featuring the band opening for rising stars Aerosmith at an auto racing venue in New Jersey. The actual listing would be

August 24, 1975 Trenton Speedway, New Jersey State Fairgrounds, Hamilton Township New Jersey
Aerosmith/Kingfish/Poco/Slade/Nils Lofgren/Mohagany Rush/Hootchie Kootch

The concert was a Sunday afternoon event beginning at 1:00 pm. Trenton Speedway was a 1.5 mile oval track (IndyCar/NASCAR) inside the New Jersey State Fairgrounds. Hamilton Township is the town right next to the capital city of Trenton, so both the Fairgrounds and and the Speedway were usually referred to as in Trenton. The ad prior to the concert is from the Bucks County Courier Times of August 15, 1975. Promoters Hollow Moon Productions apparently insisted that only 8000 people would be allowed inside the bowl of the oval track of the concert.

The promoters seemed to have underestimated the appeal of Aerosmith, whose album Toys In The Attic had been released in April and was steadily climbing the charts. The first single from the album, "Sweet Emotion," was climbing the charts, and "Walk This Way" would follow later in 1975. By the next year, an earlier single, "Dream On" had re-entered the charts, and Aerosmith was one of American's biggest rock bands. Hollow Moon productions correctly anticipated that Aerosmith could headline an 8000-ticket event, but even they must have been caught by surprise at the turnout.

As the post-mortem review from the Bucks County Courier Times on Monday (August 25, 1975) revealed (above), the concert rapidly gotten out of hand. A huge crowd stormed the chain link fence, and despite the best efforts of baseball bat wielding security staff, eventually everyone was let in for free. The problems at this concert were still being mentioned in the Courier Times the next Summer, and seem to have put a damper on big outdoor events at the State Fairgounds.

Notes on the bands
Aerosmith: Toys In The Attic, released April 1975, was Aerosmith's third album. They remain major concert headliners to this day.
Kingfish: Kingfish, with Bob Weir of The Grateful Dead and Dave Torbert of the New Riders, had come together after the Dead went on a touring hiatus in late 1974. Up until this show, save for one show in Reno, the band had not played outside of California.
Poco: Poco, an excellent if not quite headlining band, was now a four-piece, featuring guitarists Paul Cotton and Rusty Young, bassist Tim Schmidt and drummer George Grantham (everyone sang). Their current album Head Over Heels (ABC Records, July 75) had just been released.
Slade: Slade was an English "Glam" hard rock group, managed by former Animals bassist and Hendrix manager Chas Chandler. Hugely popular in England, their mass appeal never translated to the United States. Nonetheless, Gene Simmons of Kiss cited them as a big influence, and Quiet Riot had huge hits with remakes of some Slade songs in the 1990s. However, the Courier Times reviewer singled out their music as "typical of...all the poorer aspects of rock music," which was a standard American response to the band.
Nils Lofgren: Guitarist/singer Nils Lofgren had played around the Northeast with his band Grin from 1969 to 1974, and he had also worked with Crazy Horse and Neil Young. He had just released his first solo album (on A&M).
Mahogany Rush: Mahogany Rush was a Canadian power trio led by guitarist Frank Marino. I saw them a few months before this (at Winterland), and I can assert that despite all protestation to the country, Marino sounded like a Hendrix knock-off. That being said, it was pretty enjoyable. Their current album was probably Strange Universe.
Hootchie Kootch: Hootchie Kootch was a local band.
note: the excellent Poco site has an ad featuring Ambrosia instead of Mahogany Rush.

Notes on the venue
Auto races at the New Jersey State Fairgrounds near Trenton had been held as early as 1900, and continuous racing began in 1912. A new oval dirt track was opened in 1946, and it was paved in 1957. It was a regular stop on the Indy Car circuit in the 1960s, where stars like AJ Foyt and Parnelli Jones raced (Jim Clark drove Indy Cars there in 1963 and 1964). NASCAR raced there with some regularity from 1967 to 1974, and Richard Petty won three Grand National Events.

The Allman Brothers Band headlined a huge show on October 7, 1973. Apparently over 60,000 attended and the concert security was completely overwhelmed, ending outdoor concerts there until the Aerosmith event.

The race track closed in 1980, and the Fairgrounds closed three years later. The site is now a huge outdoor museum called Grounds For Sculpture.