After the February Revolution of 1848, Lacrosse was elected representative of Finistère in the Constituent Assembly.

In June he was given command of the departmental national guards.

He was one of the secretaries, then one of the Vice-Presidents of the Assembly.

He then joined the Conservative party, voting regularly with the right.

After the presidential election of 10 December 1848 Lacross gave his full support to the Government of Louis-Napoleon Bonaparte, who made him Minister of Public Works from 29 December 1848 to 30 October 1849.
For a few months he was also interim Minister of the Interior.

He was reelected on 13 May 1849, representing the Finistère in the Legislative Assembly.

He fully supported the government and the majority.

He was named vice-president of the Assembly.

From 26 October 1851 to 2 December 1851 he was again Minister of Public Works.

During his two terms in this office he inaugurated the railways of the North, the East and Nantes.

He began clearances near the Louvre and prepared for its final completion.
After the February Revolution of 1848, Lacrosse was elected representative of Finistère in the Constituent Assembly.
In June he was given command of the departmental national guards.
He was one of the secretaries, then one of the Vice-Presidents of the Assembly.
He then joined the Conservative party, voting regularly with the right.
After the presidential election of 10 December 1848 Lacross gave his full support to the Government of Louis-Napoleon Bonaparte, who made him Minister of Public Works from 29 December 1848 to 30 October 1849. For a few months he was also interim Minister of the Interior.
He was reelected on 13 May 1849, representing the Finistère in the Legislative Assembly.
He fully supported the government and the majority.
He was named vice-president of the Assembly.
From 26 October 1851 to 2 December 1851 he was again Minister of Public Works.
During his two terms in this office he inaugurated the railways of the North, the East and Nantes.
He began clearances near the Louvre and prepared for its final completion.
Théobald de Lacrosse