Indian men and women dressed in colourful traditional attire hailing from different parts of India, including Punjab, Maharashtra and Gujarat, were gathering for the three-hour event, which will also see US President Donald Trump share the stage with Modi in a special gesture.
The beating of drums, cheering and shouts of "Modi, Modi" went up from among the crowd. Around 50,000 members of the Indian diaspora are expected to attend the 'Howdy, Modi!' event, for which tickets were sold out many weeks ago.
The event being held at the NRG Football Stadium, one of the largest in the US, has been organised by the Texas India Forum (TIF), a non-profit organisation.
"The energy in the stadium is palpable as the crowd awaits Prime Minister Modi's address," TIF tweeted ahead of the event that has the theme 'Shared Dreams Brighter Futures'.
It said the Indian-American community has turned out in full force for the event. "Community members have travelled from across the country to be a part of this historic event," it said.
Pranav Desai, 'Howdy, Modi!' organiser and founder of the Voice of Specially Abled People, said that thousands of volunteers are working for the event. "Proud of our PM's commitment for making our country great again," he said.
Many young Indian-Americans have painted Indian and US flags on their faces.
The Indian-American community has been busy preparing for the three-hour show that will see artistes present Indian classical and folk songs and dances, among other numbers.
More than a 1,000 Gujaratis from Houston are preparing for a mega 'dandiya', a traditional Gujarati dance, to welcome the Prime Minister for the event.
TIF spokesperson Gitesh Desai said that Indian-Americans from across the US are attending the 'historical event'.
"Some 50,0000 attendees from the Indian-American communities and people from the 48 states are attending the show. It is going to be a historical event, the largest such event held for a democratically elected head of state. No such programme has been held in the US in the past. Senators, Congressmen, Mayors and US President Donald Trump are going to attend ther event," said Gitesh Desai.
Several cultural programmes are on the anvil for the show, which has a theme 'Woven', signifying how the Indian-American community has become part of America, he said.
He added that more than 100 buses are being provided to ferry the participants.
Massive billboards have come up near the NRG Stadium and across Houston with messages of welcome for Modi, who arrived here on Saturday for a week-long visit to the US.
A car rally was also organised in Houston on Friday, ahead of the 'Howdy, Modi!' event.
( With inputs from IANS )