Answer:
Step-by-step explanation:
1. The building of the first Mosque:
The entry into Madina was followed by the building of the mosque, the first-ever for the Muslims who had just emerged from years of oppression in Makkah. It was one of the most important landmarks for Muslims who now had a centre of their own for open uninhibited gatherings, a school for learning the Qur'an and a headquarters for receiving necessary instructions from their leader.
Gone were the days of secret underground meetings in Makkah, where the fear of persecution had always weighed heavily for the faithful. Yathrib which from now onwards was Madinat-an-Nabi (city of the Prophet) or Al-Madina al Munawara (illuminated city), provided a free open atmosphere for the growth of the true faith.
Makkan immigrants mixed with the local populace, the 'Ansar' (Helpers), and cheerfully started giving shape to Islam's first-ever mosque which would be known as Masjid-an-Nabi (Prophet's Mosque). The building was soon constructed of clay and tree trunks with palm leaves serving as a thatched roof. The Messenger of Allah himself took part in the construction and the following year he enlarged its precincts to cover an area of 2475 square meters.
2. Fraternization
The second important step taken by the Prophet in Madina was the fraternizing of 'Muhajireen' (Makkan Immigrants) with the 'Ansar' (Madinite Helpers) in the bonds of Islamic brotherhood. He fraternised each Muhajir with an Ansar, joining them together as brothers in faith. And he himself clasped the hand of his beloved cousin Ali bin Abi Talib (a) as the supreme symbol of brotherhood, fraternity and solidarity in the Islamic society.
3. The Islamic State
The other important event after the Hijra was the establishment of the Islamic State and Government by the Prophet, who by applying the gradual unfolding of divine commandments, moulded the hitherto ignorant Arabs into a real Islamic society. Expounding the eternal miracle of the Holy Qur'an and setting his own divinely inspired personality as a practical example, he firmly erected the pillars of justice and virtue. In short, Prophet Muhammad (S) presented to the dark world seething under tyranny and oppression, the most perfect ever constitution - spiritual, social and political and a key to their salvation both in this mortal life and the hereafter.
4. Jihad
The next stage was Jihad or holy struggle, a thing not known in Makkah. It was the natural consequence to the setting up of a state. Unbelievers, ever-intent to stamp out the divine call but seeing Islam finely knit unto a secure state, resorted to arms, and the Muslims had to follow suit to defend their faith, and according to Allah's injunctions went out to do battle with the aggressors.
Hope this helped you!