As of 1 January 1900, the municipality of Amsterdam took over AOM.
The company continued as the Gemeentetram Amsterdam (GTA).
A total of 242 tramcars, 758 horses and 15 buildings were acquired along with the company.

Between 1900 and 1906, all but one of the existing tram lines were electrified.
Additionally, the AOM's unusual track gauge of 1,422 mm (4 ft 8 in) was converted to 1,435 mm (4 ft 8 ¹⁄₂ in) standard gauge.

By 1906, the electric tram network consisted of 12 tram lines (1-11 and 13).
To operate these lines, the GTA purchased 229 new electric tramcars.
The former horse-drawn trams were progressively reclassified as tram trailers.
In 1906, the Amsterdamse Tramharmonie orchestra (now known as Symfonisch Blaasorkest ATH) was founded.
This orchestra, composed of amateur musicians from the Amsterdam region, still exists.

The last remaining Amsterdam horse tramway was line 12 (Nassauplein–Sloterdijk), which was electrified in 1916.
Five years later, upon Amsterdam's annexation of the municipality of Sloten, a former Sloten horse tramway came under the control of the GTA.
The horses of this line, which linked Overtoom with Sloten, were replaced by tram-hauling buses in 1922; the line was converted into a conventional bus line in 1925.
As of 1 January 1900, the municipality of Amsterdam took over AOM. The company continued as the Gemeentetram Amsterdam (GTA). A total of 242 tramcars, 758 horses and 15 buildings were acquired along with the company.
Between 1900 and 1906, all but one of the existing tram lines were electrified. Additionally, the AOM's unusual track gauge of 1,422 mm (4 ft 8 in) was converted to 1,435 mm (4 ft 8 ¹⁄₂ in) standard gauge.
By 1906, the electric tram network consisted of 12 tram lines (1-11 and 13). To operate these lines, the GTA purchased 229 new electric tramcars. The former horse-drawn trams were progressively reclassified as tram trailers. In 1906, the Amsterdamse Tramharmonie orchestra (now known as Symfonisch Blaasorkest ATH) was founded. This orchestra, composed of amateur musicians from the Amsterdam region, still exists.
The last remaining Amsterdam horse tramway was line 12 (Nassauplein–Sloterdijk), which was electrified in 1916. Five years later, upon Amsterdam's annexation of the municipality of Sloten, a former Sloten horse tramway came under the control of the GTA. The horses of this line, which linked Overtoom with Sloten, were replaced by tram-hauling buses in 1922; the line was converted into a conventional bus line in 1925.
Trams in Amsterdam