Mrs Keogh spoke of the guilt and shame she had felt as a young Pakeha person when she had found out about the Treaty's history, and the journey she has been on since.
She said New Zealanders need to "celebrate their differences" and learn from one another moving forward.
"I think we need to acknowledge the grief and sadness felt in this nation because of what has happened in the past," she said.
"Waitangi Day is about commemorating and celebrating - how far we have come and how open many of us are to moving forward."
Matua Baptist elder Graham Preston spoke about the two Treaty documents and the "confusion" that resulted.
He told the crowd to find out the truth about New Zealand's history to gain a better understanding of the importance of Waitangi Day.
"I grew up in the 1950's and we were told a very different story," he said.
"The truth will set you free, but you have to do your homework and find out what happened and why it happened so you can start to think about how we can continue trying to repair it."
Tauranga mayor Stuart Crosby said progress had been made on Treaty settlements and more work would start later this year, including a joint council and iwi meeting on how to manage Mauou.
"Progress has been made and it will continue to be made," he said.
Waitangi Day was a good day to celebrating diversity, MC Turi Ngatai told the crowd.
"Because it is in our differences that we have our strength."
Waitangi Day celebrations continue around the Bay today with stalls, kapa haka, weaving and entertainment at the Historic Village on 17th Ave from 10am-5pm. Entry is a gold coin donation. Papamoa is hosting a Waitangi Day Community Fair from 11am at the beach front near Coast.