the greatest achievement of the national assembly convened in France in 1798 was

The National Assembly in France, which convened in 1789 not 1798, is known for a number of significant achievements. However, its greatest achievement is arguably the drafting and adoption of the Declaration of the Rights of Man and of the Citizen.

Here are the steps that led to this achievement:

1. The National Assembly was formed on June 17, 1789, by representatives of the Third Estate (the common people) who declared themselves a National Assembly after being locked out of a meeting of the Estates-General.

2. On August 4, 1789, the National Assembly abolished feudalism, sweeping away both the seigneurial rights of the Second Estate (the nobility) and the tithes gathered by the First Estate (the clergy).

3. On August 26, 1789, the National Assembly adopted the Declaration of the Rights of Man and of the Citizen. This document was influenced by the doctrine of "natural right", the rights the revolutionaries believed were natural to all men and not dependent on government. It stated that "Men are born and remain free and equal in rights" and set out a series of individual rights, including the rights to liberty, property, security, and resistance to oppression.

4. The National Assembly also began the process of drafting a constitution, which would lead to the establishment of a constitutional monarchy in France.

5. The National Assembly's work laid the groundwork for further revolutionary changes in France, including the end of the monarchy and the rise of the First French Republic.

So, the greatest achievement of the National Assembly convened in France in 1789 was the drafting and adoption of the Declaration of the Rights of Man and of the Citizen.