I left the Al-Ahram offices half an hour after results of Egypt's first post-Mubarak presidential poll were announced declaring Muslim Brotherhood candidate Mohammed Morsi Egypt's first non-military president. As soon as I walked out of the main gate, I could see and feel the carnival atmosphere: vehicles of all kinds packed with people waving flags and posters bearing Morsi's image, open trucks carrying shirtless men, motorcycles precariously stacked with entire families, and microbuses and taxis, all blasting their horns in celebration.

Small festive marches continued to pour into Tahrir Square – already teeming with ecstatic Morsi supporters – from Cairo's working-class Bulaq, Ramses and Shubra districts. "God is great!" they chanted. "Down with military rule!"

Howayda Ibrahim holds on to her 13-year-old son, Mohamed, who is also waving a small Egyptian flag. Both are smiling from ear to ear. "I'm happy for Egypt and Islam. God saved Egypt from the dictators," declares Ibrahim, who came from Shubra to join the celebrations in Tahrir Square – the birthplace of last year's revolution. 

Ibrahim, wearing a black dress and green headscarf, hopes Morsi will be able to deliver justice to the poor and "lives up to the expectations of the Egyptian people, who have put their faith in him to solve Egypt's chronic poverty and unemployment."

In the working-class Bulaq district, the atmosphere is no less festive, featuring fireworks, gunshots in the air and half-naked men dancing in the streets. Shopkeepers distribute free sweets to passersby.

Aymen Ali, a 29-year-old juice seller, offers free sugarcane juice to fellow celebrants.

"This is a historical victory in the long battle between good and evil," said Ali, who was unable to travel all the way to his hometown in the Upper Egyptian Sohag governorate to vote, but who is nevertheless elated by Morsi's victory. 

Ali believes that the Brotherhood "will not repeat the mistakes that it made in parliament and will now work with civil political forces against the ruling military council."

Patriotic songs play in the background at a nearby shop selling crackers and nuts. Shop owner Khaled Hashem, 53, is overjoyed.

"This is the happiest day of my life. I can finally see a bright new future for my children and grandchildren," said Hashem, a father of three. "The revolution succeeded and our demands for justice, equality and freedom will be realised. I no longer have to worry that my children will be unemployed because of rampant corruption."  

Across the street from Hashem's shop stands a near-vacant koshary restaurant. From behind big pots of rice and lentils, shop owner Mohamed Mahmoud, 57, says he is happy to have a president after 18 months of uncertainty.

"We need stability and security. We're tired; business has been terrible since the revolution, as you can see," said Mahmoud, pointing to his empty restaurant.

Mohamed Salama, a government employee, stands in front of the restaurant. "This was the best-case scenario. I'm tired after 30 years of poverty and injustice," he said. "I voted for Morsi in both electoral rounds because I support his calls for social justice and the gradual implementation of Islamic law."

Vegetable seller Abu Waleed, for his part, doesn't hide his disappointment with Sunday's poll results.

"I voted for Shafiq out of fear of the Brotherhood, which is becoming the new NDP [ousted president Hosni Mubarak's now-defunct National Democratic Party]," Abu Waleed says, puffing intensely on his cigarette. "They're very strict about religion and Islamic law and will suffocate us. Nor do they practice what they preach."

At a nearby microbus stop, Souad Mohamed, 35, sits on the pavement waiting for a ride to the working-class Imbaba district. Mohamed, too, seems less than pleased.  

"The Brotherhood will make us stay at home," said Mohamed, who works as a cleaning lady. "I have three kids and can't afford this. I'm the family's sole breadwinner."

On the 6 October Bridge overlooking Tahrir Square, cars line up to watch the festivities below.

The upscale neighbourhoods of Zamalek and Mohandeseen, meanwhile, seen largely as bastions of pro-Shafiq sentiment, were quiet for the most part.

At the entrance of Sheikh Zayed City on the outskirts of Cairo, however, the party resumed, with men and children performing traditional dances and songs. Others waved Egyptian flags and Morsi posters.

The taxi driver who took me home, for his part, expressed ambivalence. "I'm happy to see people cheering and celebrating, but I fear that the Brotherhood will become the new NDP."